S/O: Should Texas move to 100% renewable energy? If so, how could it be done?

[RegGuheert]

Who am I and why do I care about renewable energy in Texas?

I might as well start with a disclaimer so that everyone knows where I am coming from.  I am a conservative retired electrical engineer who lives in Northern VA.  I am also a big fan of photovoltaic solar electricity production.  I installed an off-grid photovoltaic system on our property over 21 years ago and an on-grid system 10 years ago.  About 6 years ago I upgraded the old off-grid system to be on-grid.  I recently purchased another 3.7 kW of solar panels and am in the process of adding them to our roof.  We have a 9-year-old Nissan LEAF electric vehicle and several gasoline-electric hybrid vehicles.  We also have two gasoline vans and a diesel tractor.

I frequently hear overly-pessimistic anti-renewable rhetoric from conservatives that I know and I also frequently hear overly optimistic pro-renewable rhetoric from liberals that I know.  The same is true about their views on electric cars.  The simple truth is that there are things that renewable energy does well and there are things renewable energy does not do well.  In other words, I do not believe in one-size-fits-all for when it comes to energy

I am particularly interested in Texas because I personally believe that it has the best chance of any state in the continental U.S. to convert EVERYTHING THAT USES ENERGY to solar and/or wind power.  But that doesn't mean it should be done or even that it could be done.  Hence this thread.

Oh, BTW, I am not a big fan of wind power.

Why talk about Texas?

It's certainly topical!

I saw a quote yesterday:  "Not having energy in Texas is like starving to death in a grocery store."  There is a lot of truth to that.  It's the main reason public officials will have a lot to answer for regarding the ongoing debacle.  With the exception of hydroelectric and geothermal resources (and perhaps uranium), Texas is blessed to have massive energy resources including oil, natural gas, wind, and solar.  (Does Texas have much coal?) Texas also has a warm climate (usually!).

So there are two questions:

1) Given all of the solar and wind resources available in Texas, is it possible for Texas to convert to 100%* solar and/or wind energy in the near future?  If so, how would this be accomplished?

and

2) Regardless of whether or not 1) above is true, does it make sense for Texas to make a goal to move toward 100%* solar and/or wind energy?  Why or why not?

* And to be completely clear here, I am NOT talking just about electricity.  I am talking about electricity, heating, transportation, industrial...everything.

I'll break the thread starter here so that others can join in.  Please, let's keep the politics out of this and think about what makes the most sense for Texas and for Texans.

[RegGuheert]

18 minutes ago, RegGuheert said:

1) Given all of the solar and wind resources available in Texas, is it possible for Texas to convert to 100%* solar and/or wind energy in the near future?  If so, how would this be accomplished?

I believe that "Yes!" this could be done using today's technology.  I will go further and say that Texas could meet their entire energy needs with photovoltaics for all energy production, battery storage for overnight needs and synthetic natural gas for seasonal load shifting, some transportation, and emergency electricity backup using existing natural gas generators.  Here are the key factors, IMO:

- Texas has massive solar and wind resources which are much more than sufficient than what is required to meet the need.

- Texas is at a latitude where the solar resources are closely aligned with the load requirements.  With some help from @chiguirre, I posted about this fact here yesterday.  Because the electricity load is only slightly shifted in time versus the load, I recommend that the solar simply be oversized and that any overproduction should be used for charging batteries and or synthesizing natural gas for storage and later use.

- Texas has a warmer climate where wintertime loads are minimized.  (Those of you in the panhandle will have to correct me here if I am wrong!  Is your climate more like, say, Missouri?)

- Electric vehicles can be employed for both transportation and for overnight/emergency electricity storage.  This will require electric vehicles to charge during the daytime rather than at nighttime.  For reference, in Texas it takes about four 60-cell PV panels to power one typical electric vehicle (or three 72-cell PV panels).

- About 40 60-cell PV panels can meet the electricity needs of a typical single-family home in Texas (or about 33 72-cell PV panels).

- Additional storage batteries will be needed at homes for when the vehicle is not available to capture additional production.  These batteries have about a 90% round-trip efficiency.

- Electric buses, electric heavy trucking, and electric trains can round out the transportation infrastructure.

- Electricity can be used to convert water and CO2 into methane.  A fellow Texan, Elon Musk, is working on developing advanced, efficient systems to do this to enable a return trip from Mars.  (In addition, Elon Musk is applying for permits to drill wells for methane!)  This methane can be used in the existing storage, distribution, and utilization facilities to provide heat, electricity, and industrial feedstocks.  This will allow for the existing fossil fuels to be used during the transition to synthetic fuels and will ensure a seemless movement to renewables.

- I think the biggest challenge I can see with this idea may be farming.  Farm equipment typically runs on diesel fuel.  Does any of the farm machinery in Texas run on natural gas to take advantage of the abundance there?  Even if it is not done today, it is certainly something that can be done using existing technology.

[Ausmumof3]

I don’t know much about the ins and outs but our state power supply was a disaster six years ago with rolling black outs and on hot days, etc culminating in a massive storm that took out a major interstate connector and leaving the entire state with no power.  Including backup power systems to at least one hospital temporarily.  A Fertility clinic lost a lot of embryos.  
 

The state signed some kind of deal with Elon Musk to build a giant battery system and we haven’t had an issue since.  You can read a bit more here.  It also seems to have somewhat stabilised power prices that were escalating insanely.  We don’t have any nuclear power so aside from wind and solar it’s all coal.

https://www.popularmechanics.com/science/a31435906/how-elon-musk-battery-farm-works/

Edited February 17, 2021 by Ausmumof3

[chiguirre]

Texas isn't really a "long term plan" kind of a state. It's more a "look for the fast, cheap, easy option" sort of a place. If renewables are cost competitive, they'll win. That's why we have so much wind power, and that's why the wind turbines aren't winterized. (And neither is the natural gas infrastructure.)

I do think that we'll inevitably move to more renewables as their cost comes down. The same goes for electric vehicles. 

[Sdel]

I’ll bite.  Pretty conservative household here...we are pretty open to renewables and think they are great and maybe have a great future....but for todays tech are best viewed as supplements that are more akin to prepper lifestyle.  Everyone should have access to enough solar/wind personally to get through in a pinch.  Our future plans for our property include propane tank, solar and possibly some wind since we are the highest point overlooking a valley.  Everything has it’s trade offs and honestly diversity is best.  I don’t think the tech will get there without a major event spurring the money to go there.  Just human nature.
 

There are many primary coal plants in TX.  They’ve been converted to run on their backup generation that uses natural gas instead....and all newer plants are natural gas only.  The coal industry in TX is probably almost dead.  This is an economic decision that is being made because natural gas became very cheap and available with fracking.  If you take them at their word, gas distribution went down at the well sites.....those sites and pipeline are to be maintained by the oil and gas operations.

I do have to give my local power a big shout out....they were required to drop 40% of the load.  We do have areas that have damage relate outages but overall as a community I think we’ve been sharing pretty well.  I haven’t been able to compare experiences.  One of my stepson’s has not lost power.  He’s near the hospital/high school/ govt offices so that is probably why.  We had an 8 hour outage the first night, but since then we’ve had steady rolling outages of predictable length and the outage map has a consistent 1/3 to 2/3 ratio.  My aunt in Ft Worth hasn’t had power since the beginning.  I firmly believe the difference is that our local plant was continued as a not for profit quasi-gov’t entity and remains closely tied to our community after deregulation while other companies are run more like private businesses.
 

As for farm equipment on natural gas.....that is probably going to be a hard no for a long time.

[RegGuheert]

6 minutes ago, Ausmumof3 said:

The state signed some kind of deal with Elon Musk to build a giant battery system and we haven’t had an issue since.  You can read a bit more here.  It also seems to have somewhat stabilised power prices that were escalating insanely.  We don’t have any nuclear power so aside from wind and solar it’s all coal.

https://www.popularmechanics.com/science/a31435906/how-elon-musk-battery-farm-works/

Thanks!  I'll have a look at the article today if I get a chance.

I'm a big fan of many thing that Elon Musk has done, including his batteries.  That said, the technology in the Tesla batteries is great for cars, but I'm not convinced it is the best solution for daily cycling applications.  The price is not quite right for stationary storage, either.  Utilities can sometimes justify that cost because they are trying to solve expensive problems.

BTW, does the coal used in Texas come from Texas, or from elsewhere?  (That figures into this equation in my opinion.)

[Ausmumof3]

1 minute ago, RegGuheert said:

Thanks!  I'll have a look at the article today if I get a chance.

I'm a big fan of many thing that Elon Musk has done, including his batteries.  That said, the technology in the Tesla batteries is great for cars, but I'm not convinced it is the best solution for daily cycling applications.  The price is not quite right for stationary storage, either.  Utilities can sometimes justify that cost because they are trying to solve expensive problems.

BTW, does the coal used in Texas come from Texas, or from elsewhere?  (That figures into this equation in my opinion.)

I believe they are also working on some small scale projects here where they set up a battery and solar panels to service a group of houses.  People don’t pay for the system and get discounted power supplies at this stage although long term it won’t be that good a deal it’s a promotional thing.  The other thing with solar here is with a lot of remote or farm properties if they’re building new it’s often cheaper to install a solar system than connect to the mains electricity especially if there’s a bit of distance involved.  

[RegGuheert]

11 minutes ago, chiguirre said:

Texas isn't really a "long term plan" kind of a state. It's more a "look for the fast, cheap, easy option" sort of a place. If renewables are cost competitive, they'll win. That's why we have so much wind power, and that's why the wind turbines aren't winterized. (And neither is the natural gas infrastructure.)

I do think that we'll inevitably move to more renewables as their cost comes down. The same goes for electric vehicles. 

Yeah, I'm not in favor of the government doing this kind of planning because they have a way of screwing up even the best ideas.  Still it is interesting to have a look and see where we are.  I think I will make a post to show what it would cost to move just a single household to PV and EV, with and without storage.

That brings up a good question:  Does anyone have access to hourly electricity usage in a hot part of Texas during the summertime.  I'd be interested to see what happens at night.  (I know what goes on here in the wintertime and it is NOT pretty!)

I agree that electric cars and trucks are inevitable pretty much everywhere.  Photovoltaics are likely inevitable at lower latitudes.  Beyond that, things get much, much more complicated.

[Sdel]

As far as I know locally, yes, coal is produced and used locally.  Our closest coal plants are about an hour away.  We have a friend that works at one and he’s always afraid of closing/layoff being a month or two away.

[RegGuheert]

1 hour ago, Sdel said:

Pretty conservative household here...we are pretty open to renewables and think they are great and maybe have a great future....but for todays tech are best viewed as supplements that are more akin to prepper lifestyle.

I will say that is my view of yesterday's tech.

I wasn't planning on adding more solar to my house, but one of dw's coworkers recently asked me for advice on bids he was getting for a solar system.  When I saw the prices for equipment these days, I decided I couldn't pass it up.  I spent about $3000 (unsubsidized) for 3.7kWp of solar panels and mounting hardware and I expect to get that entire amount back over the next six years (through the magic of net energy metering, which IS a form of subsidy).

With today's prices for photovoltaics, you can purchase the entire kit of equipment to provide all of the electricity for a typical house in Texas for about $12,000 with a 25-year warranty on everything.  If you are handy and can install it yourself, you can build a system and through net energy metering you can recover your entire cost in about eight years.  That system will produce ever-valuable electricity for more than 25 years, paying back 4X to 5X of the expense.

If you are not comfortable installing it yourself, then your costs increase significantly: expect to pay another $24,000 to have someone else install the system above.

Batteries are still expensive today, but the technology is now reliable and durable.  Figure about $30,000 to $40,000 for the battery for the house above, installed (most of these do not allow self-install).  The battery warranty is only for 10 years, currently.  Since I have net energy metering available to me, I have avoided the cost of batteries so far.  Electricity utilities are fighting, and winning, the battle to eliminate the subsidy with is net energy metering.

So, yes, you can build a maintenance-free, standalone photovoltaic system with existing products today, but it will cost about $75,000 for the typical Texas house with storage.  I doubt that the photovoltaic equipment will come down much more, nor will installation costs.  The battery is the part which costs serious money for today and I expect massive drops in price over the next decade or so.

[Sdel]

21 minutes ago, RegGuheert said:

So, yes, you can build a maintenance-free, standalone photovoltaic system with existing products today, but it will cost about $75,000 for the typical Texas house with storage.  I doubt that the photovoltaic equipment will come down much more, nor will installation costs.  The battery is the part which costs serious money for today and I expect massive drops in price over the next decade or so.

See, that’s exactly what I mean by “not there yet” and we won’t get there until the tech catches up enough to lower the cost naturally or a major enough event forces  the money to flow there on purpose.  Until it is a cost the population will/can bear it’s too far in the future to be realistic.

[Carrie12345]

I don’t know enough about Texas to speak for their situation.  That said, I want to be all-renewable and feel like the potential is there (here in PA) if it were only more affordable.

I do live near a large venue that runs off of a large solar field and love to watch the goats providing grass management, lol.

I switch my electric supplier between wind and solar when my contracts are up. I’d prefer to be off-grid, but it is what it is.

[RegGuheert]

1 minute ago, Sdel said:

See, that’s exactly what I mean by “not there yet” and we won’t get there until the tech catches up enough to lower the cost naturally or a major enough event forces  the money to flow there on purpose.  Until it is a cost the population will/can bear it’s too far in the future to be realistic.

Yes, it is expensive if you need the batteries, which is what I am proposing upthread.  That said, such a system is significantly more fault tolerant than what is in place in Texas today.  Massive redundancy.  I wonder how many people who just took over $100,000 worth of damage will find $75,000 to be quite cheap.

On the other end, the $12,000 number is a no-brainer, IMO.  No backup, but one of the best investments you can make today.

[Carrie12345]

43 minutes ago, RegGuheert said:

So, yes, you can build a maintenance-free, standalone photovoltaic system with existing products today, but it will cost about $75,000 for the typical Texas house with storage.  I doubt that the photovoltaic equipment will come down much more, nor will installation costs.  The battery is the part which costs serious money for today and I expect massive drops in price over the next decade or so.

With the term “typical “ though... an average day is one thing, and the rare freeze is another. My PA house is on target to exceed 4000kWh for February without an alternative heat source. (We do have a very inefficient fireplace insert.). I don’t know that an average system would eliminate pipe bursts without building to cold weather codes.

[RegGuheert]

5 minutes ago, Carrie12345 said:

I don’t know enough about Texas to speak for their situation.  That said, I want to be all-renewable and feel like the potential is there (here in PA) if it were only more affordable.

I do live near a large venue that runs off of a large solar field and love to watch the goats providing grass management, lol.

I switch my electric supplier between wind and solar when my contracts are up. I’d prefer to be off-grid, but it is what it is.

While I think the technology is all in place to handle Texas (if a bit expensive), I think we are a LONG way from being ablte to make this work in New England (or does Pennsylvania consider itself to be mid-Atlantic?  Something else?)

We have been generating roughly all of the net amount of electricity used by our nearly-all-electric (except the cooktop) home in northern VA for about 10 years, including fuel for one EV.  But being net zero is much different from being able to meet the electricity needs in real time.  I will post some data on this when I have a chance.

[RegGuheert]

4 minutes ago, Carrie12345 said:

With the term “typical “ though... an average day is one thing, and the rare freeze is another. My PA house is on target to exceed 4000kWh for February without an alternative heat source. (We do have a very inefficient fireplace insert.). I don’t know that an average system would eliminate pipe bursts without building to cold weather codes.

Yes, that's the big issue, particularly up here farther from the equator.  The worse night I know of in this house was 150kWh in a single day!!

Things are MUCH more manageable in Texas, even if there is extreme weather.  Yes, this week's even would have been an issue, but no one with the system I just mentioned would have been without electricity for anywhere near the amount of time that many are reporting.

[Carrie12345]

2 minutes ago, RegGuheert said:

(or does Pennsylvania consider itself to be mid-Atlantic?  Something else?)

I don’t know, I’m a native New Jersean with an identity crisis, lol.

[Sdel]

48 minutes ago, RegGuheert said:

Yes, it is expensive if you need the batteries, which is what I am proposing upthread.  That said, such a system is significantly more fault tolerant than what is in place in Texas today.  Massive redundancy.  I wonder how many people who just took over $100,000 worth of damage will find $75,000 to be quite cheap.

On the other end, the $12,000 number is a no-brainer, IMO.  No backup, but one of the best investments you can make today.

You do realize that 75k is about half the value or more of the majority houses in TX.  Some areas and housing costs that is more than the value of the house.  Well, I don’t know anyone who has that much to spend on it, and I don’t think your numbers are accurate for here.  It’s oil and gas country here.  Personal solar is very niche.....aka big price tag even with the subsidy.  This event is not going to help the mentality either....except for those who are already the gung-ho want to be independent types.  Until your average 50,000k/yr wage earner can afford to install or buy/rent a house ready built with one, or we decide to allow the gov’t to fully vest everyone in it....it’s unrealistic.  

[RegGuheert]

28 minutes ago, kand said:

I know we’re talking Texas, but I wanted to say that solar is much more feasible farther north than people tend to think. I’m at a similar latitude as Portland, OR. Lots of people have some solar providing some power for them, and I know a couple that get most of their power that way.

Agreed, grid-tied solar is a good idea, but note that those purchases were subsidized by both the state of Washington and the federal government AND net energy metering is also a form of subsidy (it is like renting an infinite battery for free).  I also have friends near Seattle that I know from online and their solar array produces 1/6 as much electricity in the wintertime as it does in the summertime and about 1/2 as much as the same-sized array would produce here in VA.

By comparison, a solar array the size of mine would produce nearly 50% more electricity in Texas as mine does here.  The bottom line is that in the middle of winter, a solar array in Texas will produce perhaps 5X as much electricity as the same-size array would produce in Seattle.  And in Texas, wintertime is not their peak consumption period.

EVs certainly do make a lot of sense up there since most (all?) of your electricity comes form hydroelectric power plants.  No need to burn fuels to drive when you have cheap, clean electricity available.

[TexasProud]

3 hours ago, Sdel said:

You do realize that 75k is about half the value or more of the majority houses in TX.  Some areas and housing costs that is more than the value of the house.  Well, I don’t know anyone who has that much to spend on it, and I don’t think your numbers are accurate for here.  It’s oil and gas country here.  Personal solar is very niche.....aka big price tag even with the subsidy.  This event is not going to help the mentality either....except for those who are already the gung-ho want to be independent types.  Until your average 50,000k/yr wage earner can afford to install or buy/rent a house ready built with one, or we decide to allow the gov’t to fully vest everyone in it....it’s unrealistic.  

Yes!!!  Most of the housing here is 100,000 dollars or less.  There is no way they could afford that. Not feasible.

[Ausmumof3]

It is significantly less than $75,000 to get solar installed here.  Even with full batteries etc.  I think the better solution in urban areas is where neighbourhoods hook up to a mini solar grid so you get the benefits of that without every single person having to have a battery stored on their property.  Here there are interest free loans available for this sort of thing as well, so you can pay it back instead of paying power bills.  I will post if I can find examples of a set up.

[Ausmumof3]

Another thing I’ve heard of that’s interesting is a kind of closed combined water solar system.  Basically you use the day time solar to run a water pump and pump water to a header tank.  The water is then slowly sent down through the night to generate overnight power.  I’m probably not using exactly the correct terminology and I think there are various issues to be overcome but it seems like an interesting concept.

I think we are just short of 20 pc renewable here. Diesel for farm vehicles etc will be a massive problem and potentially so will disposal/recycling of materials in batteries and solar panels in time.

[Ausmumof3]

You can see examples of solar system package costs here, bear in mind this is Aussie dollars so probably in comparison you would take off roughly 30pc.  Equally any variations etc will increase the cost.  Also there are some government subsidies that may be included.

https://greenbuildsa.com.au/off-grid-solar-adelaide/

[Carol in Cal.]

I have to say, while I think that this topic is absolutely fascinating, it hurts my heart to see it here right now.

Last summer when the fires were burning people alive here, literally, if there had been a thread titled “Should California require all fireproof structures and retrofits?” ... that would have been crushingly hurtful.  Maybe wait a couple of weeks, K?

[Spy Car]

10 hours ago, TexasProud said:

Yes!!!  Most of the housing here is 100,000 dollars or less.  There is no way they could afford that. Not feasible.

I'm trying to wrap my head around this idea. In most of CA that's not a down payment.

Bill

 

[Spy Car]

Hey Reg, I think you have far more expertise on this issue than I do, but the way I figure it man-made climate change is real and what just happened in Texas is only further evidence of the idea if we don't figure out how to maximize clean and renewable energy worldwide and minimize carbon emissions and the like that these events are only dress rehearsals for larger catastrophes to follow.

We will likely need to find creative mixes as we transition our economy to cleaner fuels, but we need to get moving at a quicker pace. Like the health of the planet depends on it.

Bill

Edited February 18, 2021 by Spy Car

[Laura Corin]

Returning to my point in another thread, investing in decent insulation can be a lot cheaper than the equivalent emissions reduction through clean generation.

FWIW, we have moved into a new house that has a good south-facing roof suitable for solar panels; we are a long way north, so get light something like 20 hours a day during the sunniest months.  In the renovation that we are planning (once the pandemic gods allow us to welcome tradespeople into the house) we are planning to spend money on interior insulation of the stone walls and renovation of existing solid wooden shutters.  We'll see if solar is in the budget after that.

Edited February 18, 2021 by Laura Corin

[Shoeless]

3 hours ago, Carol in Cal. said:

I have to say, while I think that this topic is absolutely fascinating, it hurts my heart to see it here right now.

Last summer when the fires were burning people alive here, literally, if there had been a thread titled “Should California require all fireproof structures and retrofits?” ... that would have been crushingly hurtful.  Maybe wait a couple of weeks, K?

Yes, the idea that $75K for solar is a bargain compared to $100K in storm damage (which would be covered by insurance), is feeling a bit "let them eat cake" right now.

Most of my neighbors live in doublewides that cost way less than $75K. They don't have $75K for solar panels and a battery. 

Texas is a big place. Not everyone here is wealthy. 

[Ausmumof3]

https://www.abc.net.au/news/rural/2019-12-03/microgrids-set-to-transform-how-we-use-energy/11756672
 

I found the article about micro grids I was thinking of.  I think subsidising this sort of thing might be a good option in areas without the money to do solar independently.

[RegGuheert]

7 hours ago, Ausmumof3 said:

Another thing I’ve heard of that’s interesting is a kind of closed combined water solar system.  Basically you use the day time solar to run a water pump and pump water to a header tank.  The water is then slowly sent down through the night to generate overnight power.  I’m probably not using exactly the correct terminology and I think there are various issues to be overcome but it seems like an interesting concept.

I think we are just short of 20 pc renewable here. Diesel for farm vehicles etc will be a massive problem and potentially so will disposal/recycling of materials in batteries and solar panels in time.

That sounds like a pumped storage system, and, no, I haven’t seen a closed version for a house before.  Usually, you need quite a bit of “head” (altitude difference between the storage location and the turbine) to get any significant generation out of hydroelectric.  Do you have a link for this?  I’d like to learn more about that!

Texas generates more renewable electricity than any other state in the United States (a fact that Californians do not want widely publicized!) due to their massive wind generators out in west Texas, but as a percentage of their total electricity generation I read that they were right at 25% at the end of 2020.

At this point, I will point out that Texas currently has almost no electricity storage infrastructure.  THAT is THE major hurdle that must be addressed before very high levels of renewable penetration can be achieved.  I see that Texas currently has over 77 GW (!!) of photovoltaics planned, which I think they need.  As discussed upthread, solar production matches the load in Texas very closely.  I’m sure the same is true in much of Australia.

[TexasProud]

4 hours ago, Spy Car said:

I'm trying to wrap my head around this idea. In most of CA that's not a down payment.

Bill

 

Yes. I was living in a 3 bedroom house we bought for 100,000 when I went to a cousin,s wedding in San Jose and stayed with my uncle. His house was the same size as mine and was worth 1.5 million. I could not wrap my mind around how people ever afford a house out there. They bought the house in the early 70’s before it went nuts.

 

[RegGuheert]

7 hours ago, Ausmumof3 said:

You can see examples of solar system package costs here, bear in mind this is Aussie dollars so probably in comparison you would take off roughly 30pc.  Equally any variations etc will increase the cost.  Also there are some government subsidies that may be included.

https://greenbuildsa.com.au/off-grid-solar-adelaide/

Wow! Those are good prices!  The "Package 3 : Large to Extra Large Households" is very similar to what I am specifying for the typical Texas house.  They price that at "From $42,000 + GST".

My only guess about how that could be so much cheaper is that my prices were entirely unsubsidized (even though subsidies are available) because I want to make an apples-to-apples comparison to existing infrastructure, etc.  Do you know if those numbers include a subsidy?  If so, how much is the subsidy in Australia?

One thing I do not like about that particular package is that it uses string inverters, meaning that the solar panels are connected in strings and then connected to the inverters.  The string of solar panels produces high-voltage DC, which can be quite dangerous, both from the standpoint of shock risk as well as from the standpoint of fire risk.  It is the existence of string inverters which causes many firefighters in the U.S. to be taught that if a house has solar panels on to, let it burn because it is too risky to fight the fire.  This is true EVEN AT NIGHT, because the floodlights the firefighters use cause the high-voltage DC to return.

I prefer microinverters, which invert the DC to AC at each solar panel, thus eliminating the high-voltage DC and making the wiring much more similar to all of the other AC wiring in the home, which is very safe, both in terms of shocking hazard and in terms of fire safety.

Here is a short video which demonstrates the fire danger that exists with string inverters.

[Ausmumof3]

11 minutes ago, RegGuheert said:

Wow! Those are good prices!  The "Package 3 : Large to Extra Large Households" is very similar to what I am specifying for the typical Texas house.  They price that at "From $42,000 + GST".

My only guess about how that could be so much cheaper is that my prices were entirely unsubsidized (even though subsidies are available) because I want to make an apples-to-apples comparison to existing infrastructure, etc.  Do you know if those numbers include a subsidy?  If so, how much is the subsidy in Australia?

One thing I do not like about that particular package is that it uses string inverters, meaning that the solar panels are connected in strings and then connected to the inverters.  The string of solar panels produces high-voltage DC, which can be quite dangerous, both from the standpoint of shock risk as well as from the standpoint of fire risk.  It is the existence of string inverters which causes many firefighters in the U.S. to be taught that if a house has solar panels on to, let it burn because it is too risky to fight the fire.  This is true EVEN AT NIGHT, because the floodlights the firefighters use cause the high-voltage DC to return.

I prefer microinverters, which invert the DC to AC at each solar panel, thus eliminating the high-voltage DC and making the wiring much more similar to all of the other AC wiring in the home, which is very safe, both in terms of shocking hazard and in terms of fire safety.

Here is a short video which demonstrates the fire danger that exists with string inverters.

It most likely does as they usually advertise that way to make the prices look good.  I did a quick google and the current rebate on home battery systems is $3000.  I think the rebates in the actual panels have been phased out but I may be wrong.  I’m pretty sure when we looked into ours they were one of the cheaper companies but dh didn’t feel the system was as good (bearing in mind that we don’t have batteries though).  There was a surprisingly large range between highest and lowest pricing.  They were just the first ones I pulled up, but I do know of people who have set up home battery systems for well under $75,000 (but possibly with help of qualified friends/family).   
 

I don’t understand the technical details about the fire risk, but I do tend to keep an eye on the fire jobs page and there’s quite often calls for solar panels smoking etc.  although high voltage transmission lines are a massive fire risk of another type of course.
 

 

[RegGuheert]

8 minutes ago, Ausmumof3 said:

I’m pretty sure when we looked into ours they were one of the cheaper companies but dh didn’t feel the system was as good (bearing in mind that we don’t have batteries though).

...

I don’t understand the technical details about the fire risk,

Please watch the video. you don't need to understand the details to appreciate what that 4200-degree arc can do once you see it!

We don't have batteries, either.  We cannot justify the cost when we are allowed to use the "infinite battery" for free right now.  We have a nice generator for emergencies.

That said, one of my online solar buddies in North Carolina (which is the neighboring state immediately south of Virginia) told me that they just changed to solar interconnection laws there.  As a result, solar users pay substantially more for electricity usage than do other customers.  The old systems (like his) are grandfathered in for another six years.

He told me that his utility is working closely with the big utility in Virginia to get similar laws passed here soon.  Fortunately, I am not on Dominion Power because they sold our rural area of the grid to a smaller co-op about 10 years ago, but if the laws change in the whole state, I expect my rate plan will, too.

As a result, I am looking closely at battery systems.  The new ones look to be extremely efficient (>89% round-trip efficiency AC-to-AC) and very low-maintenance, hence my comment above that they are not the type of systems that preppers have.  (I had one of those and I HATED dealing with the batteries!!)  But they ARE expensive.

[RegGuheert]

5 hours ago, Spy Car said:

but the way I figure it man-made climate change is real and what just happened in Texas is only further evidence of the idea if we don't figure out how to maximize clean and renewable energy worldwide and minimize carbon emissions and the like that these events are only dress rehearsals for larger catastrophes to follow.

That's not what the recent science says.  Yes, that is what was proposed based on a study published in 2014 based on only 23 years of data.  Here is a letter published in Nature in November, 2020, that refutes that claim based on forty years of data: Weakened evidence for mid-latitude impacts of Arctic warming. As shown in the paper, what looked like wintertime cooling trend in the mid-latitudes based on only 23 years of data is actually a wintertime warming trend when viewed over the longer period.

As I said in the header post, my conservative friends tend to demonize renewables while liberal friends tend to project them as a savior.  I suspect the truth is to be found somewhere in between and it is much more nuance than "renewables bad" or "renewables good".

Personally, I do not believe that the wind generators are the cause of the ongoing catastrophe (in fact, that seems quite clear) nor do I think polar vortex is a new or increasing threat.  Here is an energy expert from the University of Houston pointing out that "we've had four or five since I moved to Houston more than forty years ago".

I understand that you and others feel that climate change is the justification for question 2) that this *should* be done.  But if you take that position, I will challenge you all (y'all is appropriate in a Texas thread?) to demonstrate that Texas converting to renewables will improve the situation there.  IMO, that is a very tall order indeed.  In addition, the *could* question is still a very important one.  As I said, I think it can be done there, but I also think it will be quite a lot of work and expense, even in Texas.  And I consider Texas to be the low-hanging fruit in the U.S., after Hawaii.

[Spy Car]

8 hours ago, Laura Corin said:

Returning to my point in another thread, investing in decent insulation can be a lot cheaper than the equivalent emissions reduction through clean generation.

FWIW, we have moved into a new house that has a good south-facing roof suitable for solar panels; we are a long way north, so get light something like 20 hours a day during the sunniest months.  In the renovation that we are planning (once the pandemic gods allow us to welcome tradespeople into the house) we are planning to spend money on interior insulation of the stone walls and renovation of existing solid wooden shutters.  We'll see if solar is in the budget after that.

It is a good point. Things like insulating homes, building with energy savings in mind, and using cleaner energy are things that can work in tandem--as I'm sure you agree.

Bill

[RegGuheert]

On 2/17/2021 at 8:32 AM, Ausmumof3 said:

The state signed some kind of deal with Elon Musk to build a giant battery system and we haven’t had an issue since.  You can read a bit more here.  It also seems to have somewhat stabilised power prices that were escalating insanely.

It is interesting that you bring this up now.  I just ran across this video showing that Elon Musk really does believe in using his own products.  It shows that they have a medium-sized Tesla solar array and some Tesla storage batteries at their Boca Chica, TX, Starship launch site and this installation helped keep the lights on during this whole debacle.

That's one thing I like about him:  If he makes a product, he uses it.  They've been testing the Tesla Semi truck by carrying batteries from their Gigafactory in Utah to the assembly plant in Fremont, CA.  The route is a difficult one through the Rocky Mountains with significant climbs and drops.  They've been pretty tight-lipped about the performance of their Tesla Semi prototypes on this tough journey, so it will be interesting to see if they really to use them for the actual logistics for their own products.  Good on them if they do!

[RegGuheert]

Let's have a look at some solar production and consumption data for an all-electric home to see what things look like in wintertime.  This data is from my home, which is in VA rather than TX, but we can use it to help understand what is needed to try to completely away from grid-based power and become self-sufficient.

For reference, the house was built in around 1993, so it is not the most efficient construction available.  The solar array has a DC power rating of 13 kW and an AC power rating of 12.6 kW.  Those ratings are a bit confusing to many people, so I will try to simplify it.  First, I will point out that kW stands for kilowatts, which is a measure of the FLOW of electricity, also known as power.  (It does NOT tell us how much ENERGY will be produced.  That is measured in kWh or kilowatt-hours, which is much more difficult to determine.)  The AC rating is the absolute maximum amount of power that the system could ever produce at any moment in time.  The DC rating of the panel is an indication of how big the solar array is.

For instance, if I wanted to compare two solar arrays on two nearby houses that were pointed in the same direction, I would use the DC ratings to make the comparison.  The AC rating simply needs to be high enough to avoid limiting the production of the array too much.  Generally and AC rating that is at least 85% of the DC rating is sufficient to do that.

Now, let's start by looking at what happens on both "good" and "bad" solar days and how things look during a "bad" month, like this one.

[RegGuheert]

The Perfect Winter Solar Day (February 8, 2021)

Let's start here, since this is what many people imagine solar production looks like.  In dry places that don't get much rain or snow, it DOES often look like this.

What was the weather like on February 8, 2021?

February 8 was a beautiful, cloudless day.  It was also cold in the morning.  When the solar inverters started up in the morning, the outside temperature was 16° F.  I think the midday temperature was around 45° F.  (BTW, I KNOW the temperature at first daylight because the solar inverters measure their internal temperature,  Unfortunately, that temperature is not as meaningful in the middle of the day because there is self-heating which changes the temperature after that initial wake-up temperature.)

Brief description of the graph:

The X-axis is time.  It goes from midnight to midnight and the day shown here is February 8, 2021.  The Y-axis is power in Watts (abbreviated "W").  The blue curve is the production of the solar array and the orange curve is the consumption of my house.

What is going on with production?

Note that the shape of the solar production resembles a cosine function if you put zero angle at noon.  But it's not quite right, is it?  The peak happens at 1:00 PM, not noon, and the curve is kind of skewed toward the afternoon.

So, why is the production curve shaped like this?  After all, the sun is just as bright in the morning as it is at noon as it is in the afternoon.  My solar array does NOT track the sun, so on a cloudless day the shape all has to do with the compass angle, the elevation angle of the array, and the path of the Sun through the sky.  It also can be affected by shadows which are created by things like other parts of the roof, trees, or possibly snow sitting on the panels.  We'll talk about clouds in a later post.  Think of holding a single solar panel in your hands.  If you hold it directly facing the sun, it will receive the most sunlight and can produce the most power.  (In this position, the Sun is said to be in the "boresight" of the solar panel, even though it is not a gun.)  If you hold it edge-on to the sun, it will produce very little power because no direct sunlight will hit the solar panel (although there will be reflected light hitting it).

The peak at 1:00PM is easy to explain:  My roof points about 14° west of South.  Since 15° is 1/24 of 360°, 15° is equivalent to one hour.  So my solar array is pointed so that its production peaks at a little before 1:00 PM.

What about the skew in shape?  Well, that is partly due to the 14° angle shift mentioned above.  Think about this:  I cannot point my solar panels due North and get a peak in production at midnight, can I?  How about if I point them due West?  Would production peak at 6:00 PM?  In the summertime, it would!  But not on February 8:  the Sun has already gone down by then.  How about directly Southwest, would it peak at 3:00 PM?  Yes!  But that production curve would rise slowly from sunrise until 3:00 PM and then it would come down rapidly after 3:00 PM.  It wouldn't look much like a cosine.  So some of the skewing is due to pointing angle.  But wait, there's more!  Some of the shape of the morning production rise is due to shadows from another section of roof which gradually clears by 10:00 AM or so.  Finally, there was a little bit of snow on a few of the panels on February 8 that did not all melt until just before noon.

Now, the less obvious part:  I said that this solar array had a DC rating over 13 kW and an AC rating of 12.6 kW, so why is the peak production shown in the image on this fully-sunny day only 11.233 kW?  Is it because it was cold?  No, actually, photovoltaic panels produce MORE electricity when they are cold than when they are hot.  The answer is that, even though it was cold that day, the sun NEVER went through the boresight of my array on February 8, 2021.  That tends to only ever happen in late March or early April and also sometime in the Fall (I'm not sure when in the Fall).

What is going on with consumption?

In the middle of the night, our load dropped down to about 500W.  That's mainly some computers, etc., that are on all the time.  I need to work on that!

But it got cold early that morning, so just before 3:00 AM the heat pump came on.  At 4:00 AM the thermostat starts trying to ramp up the temperature from 58° F toward 64° F, but it was doomed.  First of all, the heat pump is only rated to be able to efficiently move heat down to an air temperature of around 18° F.  Secondly, I had not cleaned the filter in the air handler for a couple of months before that day (I have since!).  The result is that the resistive heaters in the air handlers came on at around 6:00 AM and the heating system drew over 8 kW for HOURS until about 10:00 AM!  After the Sun came up in the sky, sunlight streams through our South-facing windows and the heat pump ramped down and then eventually turned off for the rest of the evening.

How much energy was produced?

The amount of energy produced is the integral of the blue curve, which simply means it is the area under the blue curve.  The attached image does not give you the value, but I can see it elsewhere: 73.147 kWh.

How much energy was consumed?

The energy consumed is calculated by taking the area under the orange curve: 75.526 kWh.

Bottom Line and Takeaways:

As you can see, even on a nearly-perfect solar day, we still had to BUY about 2.4 kWh of electricity from the electric company (worth about a quarter).  Why did this happen?  In an all-electric house, temperature is the main driver of the electrical load.  Below about 20° F, my heat pump reverts to resistive heating, so it is not nearly as efficient as it is at warmer temperatures.

Could we have saved energy?  Absolutely!  After I saw this data, I cleaned the air filter in the air handler the next day.  We could also turn off more electronics to further save electricity.

But, by far, most of the energy consumption that day was for heating.  75 kWh is certainly a lot of electricity, but the worst day we have ever seen in this house was twice that: 150 kWh.  Uggh!!

A Note About Storage:

February 8, 2021, is fairly instructive about daily storage requirements since it was a day when energy produced nearly matched energy consumed.  Let's imagine that all days were just like this one (that is NOT true here, but it is a much more reasonable assumption for Texas in wintertime).  How much battery capacity would be needed each night to shift the daytime production into the nighttime.  That number is given by the area between the blue curve and the orange curve during the daytime while the solar array is producing.  In other words, that is electricity which is available to be stored in batteries because it is not being used at the time of production.  I don't have the tools to calculate that number accurately, but I can estimate it from the image below.  Since we know that the area under the blue curve is roughly 75 kWh, I will estimate that the amount available for storage is around half of that, so let's say 38 kWh.

I will point out here that if we put 38 kWh into a modern Li-ion battery, we will only get about 90% of that back, or about 34 kWh will be recovered.  So our original 2.4 kWh shortfall has now grown to about 6.4 kWh once we use actual batteries for storage rather than just the infinite, perfectly-efficient battery known as the power grid.

Finally, a modern, maintenance-free, 40 kWh Li-ion battery with a 10-year guaranty about US$52,000.00.

 

[prairiewindmomma]

I don’t think large scale solar adaption is possible on a purely consumer basis. Here on the west coast, there have been a number of areas where people who want to net meter haven’t been able to get into the grid because the grid needs updating and the upgrade costs would fall on them.

Here’s what I mean: https://www.opb.org/news/article/oregon-solar-power-oregon-capacity/

 

Edited February 19, 2021 by prairiewindmomma

[RegGuheert]

8 minutes ago, prairiewindmomma said:

I don’t think large scale solar adaption is possible on a purely consumer basis.

That may very well be so, but this exercise is all about scoping the problem.  (I'm still on the "Could it be done?" question.) Most people I know (IRL and online) know next to nothing about energy and even less about renewable energy.  I suppose that is why I hear such widely-disparate opinions regarding a transition to renewable energy such as "It's impossible!" or "It will be cheap and easy!".  IMO, both of those positions are flat wrong and are based on nothing other than ignorance.

This board is about education.  My goal in this thread is to educate others who may not have access to the information I have at my fingertips.  I also hope to learn about things that I have not researched fully.  If I can get some in the "It's impossible!" crowd to realize that it is quite possible (at least in some well-suited places like Texas and at some perhaps-high cost) and some in the "It will be cheap and easy!" crowd to see that nothing about eliminating fossil fuels is cheap or easy, I will feel like I have achieved my goals.

If no one wants to step out of their comfort zones, so be it.  But I believe that most posters on this board are willing to learn about other viewpoints than the one they currently hold.  If they weren't, they'd be long gone!

[prairiewindmomma]

I am not trying to discourage solar. You asked in your OP about the feasibility of wide scale adoption, and I think it is possible AND that wide scale adoption will require the power companies or state to shoulder some of the cost of updating the grid.

I shared a local experience that I found surprising. I hadn’t heard that this was an issue until I spoke with solar companies here. In the vein of being educational—I shared my experience and info.

I live in a ‘hood where a lot of people have solar and have electric vehicle chargers. Many of them are adopting solar even though they will only break even for other reasons.... I think we will probably adopt when solar banks become available and less expensive. Perhaps that will be the work around if I can’t get on to net meter. 
 

More likely, the state will mandate upgrades to the grid in part because we are growing rapidly in our metro (like the metros of TX) and it’s less expensive and more resilient to update the grid than build another power plant expansion..

[RegGuheert]

26 minutes ago, prairiewindmomma said:

I am not trying to discourage solar. You asked in your OP about the feasibility of wide scale adoption, and I think it is possible AND that wide scale adoption will require the power companies or state to shoulder some of the cost of updating the grid.

I shared a local experience that I found surprising. I hadn’t heard that this was an issue until I spoke with solar companies here. In the vein of being educational—I shared my experience and info.

I live in a ‘hood where a lot of people have solar and have electric vehicle chargers. Many of them are adopting solar even though they will only break even for other reasons.... I think we will probably adopt when solar banks become available and less expensive. Perhaps that will be the work around if I can’t get on to net meter. 
 

More likely, the state will mandate upgrades to the grid in part because we are growing rapidly in our metro (like the metros of TX) and it’s less expensive and more resilient to update the grid than build another power plant expansion..

Fair enough.

Keep in mind that I am talking about Texas going 100% solar.  One way (almost certainly not the best way) to do this would be for everyone to disconnect and provide their own electricity.  In that case, net metering laws are irrelevant.

In fact, Hawaii passed a law a couple of years ago preventing ANY more solar electricity from being put onto the grid.  Their system simply couldn't handle it anymore.  The reason is that solar is so cheap and electricity is so expensive (US$0.45/kWh) there that everyone did it.  It is because of places like Hawaii that very well-engineered solutions now exist which allow you to stay connected to the grid, but your solar energy will never flow back that way (either with or without batteries).

I think the whole "the grid needs upgrading" on your street thing is just laziness (or should I say passive-agressiveness) on the part of the utility.  My house is connected to the grid with a wire capable of delivering 50 kW of power continuously (200-Amp service).  If you look at my plot above, neither my consumption nor my production ever approaches that number.  In fact, I have NEVER seen over 15 kW in either direction.  And I live in an all-electric house.  If I lived in the house in VA with the oldest connection type there was in the 20th century, I could draw (or deliver) 15 kWh through the wire.  On top of all of that, the power that I produce actually reduces the amount of current flowing in their wires, since I feed the neighbors houses directly and they do not draw as much through the main wire.

The real reason is that the power company has all of the grid connected up to be a LOAD.  As such, they tap all of the transformers up to near the highest voltage possible (250 VAC) so that when people draw electricity from the grid, the voltage droops but still stays above the minimum voltage (230 VAC).  When people like me start producing, that approach is no longer valid.  I have to RAISE the voltage at my house in order for the electricity to flow the opposite direction.  If I am already at the limit, I may go over.

They just don't want to have to go around and change the tap connections on all the transformers.  Wah!!

[prairiewindmomma]

Totally sincere question....

When we lived in south Texas, we had about six months out of the year where temperatures were in the high 90s/100s and moderate humidity. Our air conditioner ran through the night because even with the thermostat set at 78F, high ceilings, and tile floors, the house couldn’t maintain temps below 80F without ac. (Our ac broke in August end our 3am temperature in the house was 96F.) 

How do you self-sustain in those circumstances? I am not generating at night, but I have considerable draw when it kicks on. As I understand it, I also can’t use solely solar to run a furnace either, and I needed to December-January, when daily highs were in the 50s.

 

[Sdel]

Honestly, I think the biggest hang up about what you are talking about is that it would mean everyone would be more independent.  I’m all for it, even if it took a massive gov’t outlay, to make every home energy independent.  In my mind, independence is freedom and we’d all be freer from gov’t in our lives if our main utility was in our control.  I think that scares people and entities.  Some people would be scared of having to take over that responsibility.  The gov’t and is scared of losing that kind of control/income source.  And or course it would effect huge swaths of the economy.

[RegGuheert]

1 hour ago, Sdel said:

Honestly, I think the biggest hang up about what you are talking about is that it would mean everyone would be more independent.  I’m all for it, even if it took a massive gov’t outlay, to make every home energy independent.  In my mind, independence is freedom and we’d all be freer from gov’t in our lives if our main utility was in our control.  I think that scares people and entities.  Some people would be scared of having to take over that responsibility.  The gov’t and is scared of losing that kind of control/income source.  And or course it would effect huge swaths of the economy.

I'm with you 100% on this point.

Take a look at what I wrote in the "responsibility" thread two days ago.  I think you will see that we have the same perspective here.  The electricity utilities used to be what economists call a "natural monopoly", but new technologies are changing that so that individuals now have the ability to break free from their grasp.  There will certainly be a bit of struggle over this turf going forward.

I will also point out that a system in which each load provides its own electricity is significantly more immune to system-wide outages than the existing grid-based approach.

[RegGuheert]

1 hour ago, prairiewindmomma said:

Totally sincere question....

When we lived in south Texas, we had about six months out of the year where temperatures were in the high 90s/100s and moderate humidity. Our air conditioner ran through the night because even with the thermostat set at 78F, high ceilings, and tile floors, the house couldn’t maintain temps below 80F without ac. (Our ac broke in August end our 3am temperature in the house was 96F.) 

How do you self-sustain in those circumstances? I am not generating at night, but I have considerable draw when it kicks on. As I understand it, I also can’t use solely solar to run a furnace either, and I needed to December-January, when daily highs were in the 50s.

 

Big batteries is the simple answer.  As you can see from my plot above, my heat pump did not run all night,  That is why I have asked for anyone in Texas to provide me with hourly (or finer) consumption data from their home.  That will give us an idea how difficult (and expensive) this would be to address.

I will note, however, that cooling even at 115° F uses less energy than heating at 0° F since 115° F is only 40° F away from 75° F while 0° F is 65° F away from 65° F.  (Does that make sense?)  The point is that you will have more than 50% more heat loss in the heating case than you have heat gain in the cooling case.  Now, there will be some extra thermal load from solar heating in daytime, but that does not impact battery sizing, only the size of the solar array.