Why doesn't every house have solar installed?

[the54thvoid]

A few posts deleted.

Not allowed to venture into politics.

 

[Count von Schwalbe]

Solar works up to about Washington state for N.A.,

In July, our sunniest month, I calculate to run my A/C alone it would take around 3x the solar panel area as home area. So for every square foot of house requires 3sf of solar panel, at the correct orientation to pick up the most sun.

And I am not at Washington latitude, I am further south than San Francisco.

 

[Super Firm Tofu]

In July, our sunniest month, I calculate to run my A/C alone it would take around 3x the solar panel area as home area. So for every square foot of house requires 3sf of solar panel, at the correct orientation to pick up the most sun.

And I am not at Washington latitude, I am further south than San Francisco.

How much power are you calculating for AC?

I've got 577 sq. ft. (32 panels) on my roof, and peak power production (at best time of year, outside temp, and clear sky) generate about 65KWh per day at roughly 36° North.

 

[oxrufiioxo]

How much power are you calculating for AC?

I've got 577 sq. ft. (32 panels) on my roof, and peak power production (at best time of year, outside temp, and clear sky) generate about 65KWh per day at roughly 36° North.

My system is 14 panels 28-32KWh a day and does not cover my AC completely I'd need 7-10 more panels. I do have a 4 ton unit cooling 2400 Sq foot (single level) to around 70F with decently high 12-14 foot high ceilings though.... My system was mandated and couldn't be changed prior to closing on my house and is now complicated to upgrade or change. California FTW.

At around 78F I'd break even.

 

[Count von Schwalbe]

How much power are you calculating for AC?

I've got 577 sq. ft. (32 panels) on my roof, and peak power production (at best time of year, outside temp, and clear sky) generate about 65KWh per day at roughly 36° North.

.75 btu/h/sf peak load, 81% duty cycle, COP of 3.


Duty cycle taken from DOE paper.
COP value is about as good of an air conditioner as exists.
BTU/H/sf value is a conservative version of an industry rule of thumb.
Solar radiation value from local ASHRAE design conditions.

 

[Super Firm Tofu]

My system is 14 panels 28-32KWh a day and does not cover my AC completely I'd need 7-10 more panels. I do have a 4 ton unit cooling 2400 Sq foot (single level) to around 70F with decently high 12-14 foot high ceilings though.... My system was mandated and couldn't be changed prior to closing on my house and is now complicated to upgrade or change. California FTW.

At around 78F I'd break even.

I had mine installed at the end of 2016. I've been pretty much break-even every year. Maybe +/- $200 when all is said and done. I'm on net-metering for a yearly basis.

This covers just under 2700sq ft single level, two units, with summer temps over 100 for 3-4 months. I do keep the thermostat at 76 in the summer, and heat is natural gas. I also have two plug-in hybrid cars.

Last year's output:

 

[Count von Schwalbe]

How much power are you calculating for AC?

I've got 577 sq. ft. (32 panels) on my roof, and peak power production (at best time of year, outside temp, and clear sky) generate about 65KWh per day at roughly 36° North.

36 degrees latitude in what climate? West Coast, Southern Great Plains, Appalachian, or East Coast swamps - all very different. Even 40 miles southwest of me will be way different from simple elevation change.

 

[Super Firm Tofu]

36 degrees latitude in what climate? West Coast, Southern Great Plains, Appalachian, or East Coast swamps - all very different. Even 40 miles southwest of me will be way different from simple elevation change.

Pretty much desert. I know it varies dramatically. Rarely see rain or clouds here. Also some of the highest electric rates in the US. It's pretty much the perfect place for solar.

 

[oxrufiioxo]

I had mine installed at the end of 2016. I've been pretty much break-even every year. Maybe +/- $200 when all is said and done. I'm on net-metering for a yearly basis.

This covers just under 2700sq ft single level, two units, with summer temps over 100 for 3-4 months. I do keep the thermostat at 76 in the summer, and heat is natural gas. I also have two plug-in hybrid cars.

Last year's output:

View attachment 365942

That's one thing I'm happy about i have a heat pump that literally cost around 20-30 bucks to run in the winter at 69F a couple months I'm credited 10-20 usd. Gas is is getting super expensive also.

Pretty much desert. I know it varies dramatically. Rarely see rain or clouds here. Also some of the highest electric rates in the US. It's pretty much the perfect place for solar.

Guessing you're on socal edison... which while terrible is still better than PG&E who are both making record profits smh regardless.

I've had both over the last two years and it's shockingly expensive

I'm definitely going to have to add a second unit at some point.

 

[Waldorf]

In July, our sunniest month..

My comment was about using solar to make power, not where its able to cover all of the electric use.
ignoring for a moment its again the US, which isnt a good place to use as reference when it comes to power use/efficency of things or properly build homes, or the use of AC systems .

e.g. how many homes have you seen with 3ft or more of insulation that arent less than 2y and not made of concrete/stone?
rn imnin germany and have a single thermo panel heater running at 1kw for a few min every hour, to heat the whole (guest) house (+1000sqf) im in, while its 50F outside, my friend in the main house hasnt even turned on the heat pump, cooking/devices are enough to heat the home to a level where i would turn on AC or at least have the windows open.
in the states (DC), this wasnt enough for a room of 200sqf under the roof.

 

[Count von Schwalbe]

Pretty much desert. I know it varies dramatically. Rarely see rain or clouds here. Also some of the highest electric rates in the US. It's pretty much the perfect place for solar.

That's fair. I get cheap hydro power and a lot of clouds, even though I am also at around 36N. Not a lot of sense in solar here IMHO.

 

[Endymio]

I'm on net-metering for a yearly basis...

When you're speaking of "why doesn't every home have solar", however, it's important to note that net metering only works when a small percentage of homes use it -- it's simply a cost-shifting mechanism to allow one to use your utility company as a gigantic free battery, shifting those costs from the home owner onto all their neighbors instead.

 

[Waldorf]

but that has more to do with location as i regulations/laws etc., not with solar tech itself..

 

[Endymio]

but that has more to do with location as i regulations/laws etc., not with solar tech itself..

No, it's an innate feature of solar power, an intermittent, non-demand source. Most people think of electric supply like a water tank: something you can dump in supply whenever, and extract as needed. But if your home is drawing 3152 watts right now, your power supply needs -- at that exact moment -- generate precisely as much. No more, no less. If your array is producing more than that, you either discard it, store it in a home battery, or -- in the case of net-metering -- ask your power company to store it for you.

An appropriately-sized array will generate too much power exactly 50% of the time. In hot, sunny California, where demand peaks and sunshine are (almost) in sync, the economics of an undersized solar array used for peak-shaving makes sense. In colder climes, where the peak solar and peak demand curves are usually far out of sync, the situation is much worse.

 

[Count von Schwalbe]

No, it's an innate feature of solar power, an intermittent, non-demand source. Most people think of the electric supply like a water tank: something you can dump supply in whenever, and extract it as needed. It doesn't work like that. If your home is drawing 3152 watts right now, your power supply needs -- at that exact moment -- supply exactly that much. No more, no less. If your solar array is producing more than necessary, you must either discard it, store it in a home battery array, or -- in the case of net-metering -- ask your power company to store it for you.

An appropriately-sized array will be generating too much power exactly 50% of the time. In hot, sunny California, where demand peaks and sunshine are (almost) in sync, the economics of an undersized solar array used for peak-shaving makes sense. In colder climes, where the peak solar and peak demand curves are usually far out of sync, the situation is much worse.

More or less, hot dry climates with a standard of living that includes A/C is good for a solar/nuclear mix.

One more issue in cooler climates - the continued electrification of heating. If your power comes from a decent combined cycle natural gas plant, a high quality heat pump can make it slightly more efficient than a gas furnace.

However, electric heating for domestic (household) water is a lot less efficient unless you pony up for a heat pump water heater, which over here in the states is very expensive. With resistive heat the efficiency you get out of the natural gas can be half or less.

It does make it easier to transition to green sources, but what is there that wouldn't require substantial energy storage?

Even in my area, with a whole bunch of hydroelectric power from the TVA dams built in the 30s and 40s, we get a lot of our power from fossil fuels. This is because of a) capacity, b) low cost* and c) load fluctuation.

Hydro power is easier to fluctuate than most green sources, but only within limits. The rivers still must flow and the lakes must stay lakes.

* A lot of coal mining in the area.

 

[Waldorf]

@Endymio
guess you forgot a lot of shops/places will only be open during day hours, especially outside N.A., using power that can easily come from those running solar, and reducing load/peak load on power plants.

ignoring for a moment a plant throttling output, reduces operating cost and emissions, so its not like this has no benefit for them, nor does it require actual energy storage whatsoever.

 

[Endymio]

It does make it easier to transition to green sources, but what is there that wouldn't require substantial energy storage?

Nuclear and hydro. But both are more firmly opposed by the environmental movement than are fossil fuels.

Hydro power is easier to fluctuate than most green sources, but only within limits. The rivers still must flow and the lakes must stay lakes.

I read an estimate once that there's enough untapped hydro in Canada alone to power all North America. There's also substantial amounts here in the USA.

It's also important to remember that, even if we ran all hydro sources 24x7, the only lakes that would shrink are the artificial ones created by the hydroelectric dams themselves. When we build a dam to create or expand those reservoirs, local residents over time come to regard them as a natural feature.

@Endymio
guess you forgot a lot of shops/places will only be open during day hours, especially outside N.A....

No, I didn't forget. Most large utilities publish in real time their generation and demand curves. In cold climates, peak usage comes at night. Commercial lighting requires very little power, and most businesses still heat their facilities when closed, just to a lower temperature than a residence.

...ignoring for a moment a plant throttling output, reduces operating cost and emissions, so its not like this has no benefit for them, nor does it require actual energy storage whatsoever.

You miss the point. Read the title of this thread. If *every* home and business has a solar array, then there is no "reduced operating costs and emissions". A plant can't throttle below zero; when peak production exceeds demand, the energy must be discarded (which itself causes expensive problems, but we'll ignore that for now).

Furthermore, even when net metering *does* work on technical grounds, economically you're still cost-shifting to the utility and -- eventually -- other consumers. Forcing a utility to buy your electricity at retail ignores the fact that much of that price isn't the generation cost itself, but the cost of distribution, billing, legal, etc.

 

[Waldorf]

@Endymio dont know many other 1st world countries that heat with electricity unless its warm places that need heating for a few days a year if it gets unexpectedly cold.
ignoring that virtually all have better building codes and much better insulation, requing much less heating/cooling in the first place.

its now in the 50s during the day, and the friend im visitng hasnt even turned on heat yet, using appliances/cooking etc is enough.

and no, title says house as in living quarters, not businesses, which tend not to be inside a family home sitting in a residental area.

and i never said anything about throttling to or even below zero.

power can and gets moved around, even actoss borders, and not always consumed where its made, even before solar became common, and nothing is preventing us reducing output of 10 plants by 10% ea, i stead of just one plant to 100%, its not like this is rocket science and needs a quanum Computer to calculate for 100y to figure it out.
unless of course you belong to the power community trying to convince ppl to stay away from solar because every use would increase cost..

overall cost is relevant, not which portion is the biggest.

as i said before, i dont see the U.S. as the benchmark for what can or cant be done (anymore) or even how (its done), at least once its not about military or legal Rx drugs, many countries show they have no trouble doing what murica cant or wont.

 

[Count von Schwalbe]

It's also important to remember that, even if we ran all hydro sources 24x7, the only lakes that would shrink are the artificial ones created by the hydroelectric dams themselves. When we build a dam to create or expand those reservoirs, local residents over time come to regard them as a natural feature.

The reason for damming is for head pressure. An empty lake doesn't spin a high speed turbine.

Also, reserves are important as the multi-year drought in the US Southwest showed - Hoover dam kept the Colorado river flowing and generating from Lake Mead's reserves.

OTOH, it works great for daily fluctuations. They can ramp up and down as needed for the daily adjustment in power use. They simply have a maximum yearly cumulative energy output, equal to the amount of rainfall they receive in a year.

I read an estimate once that there's enough untapped hydro in Canada alone to power all North America. There's also substantial amounts here in the USA.

I suspect that is theoretical.

Spoiler: Thoughts on damming

The Red River, for example, crosses into Canada at the same elevation as Watts Bar dam. Watts Bar outputs a respectable 180MW, and is 112 feet tall. Unfortunately, the Red river is in a very flat part of the world. During the record floods of 97 it got to 54 feet above normal.

The only way to get electricity out of that is putting water wheels down it's entire length. Not exactly practical.

I hear that some designs of Gen 4 reactors can load balance pretty well, in addition to the improvements in safety. One of them claims a 60% turndown in 12 minutes. Could be useful to balance out uneven solar loads.

power can and gets moved around, even actoss borders,

If we could power share with solar farms in the Middle East, it would probably be a pretty viable concept.

 

[Waldorf]

im fine with existing hydro power, but all future stuff should not be based on aritificially holding water back, planet has tilted enough already, from all the water we hold back, and that was already before the big dam in china was constructed.

but some of things being worked using waves for energy, seems to be working pretty good and look viable for large scale.

 

[Endymio]

@Endymio dont know many other 1st world countries that heat with electricity

Um, if you're not using electricity for heat, you're using fossil fuels -- which voids the whole argument of using solar to reduce emissions.

And your underlying point is also wrong. Using the IAEA energy tracker, I checked various nation's per-hour energy use for January of this year. Southern European nation like Spain, Italy, Greece, and even France had peak electricity consumption at 8pm to 10pm, as did Japan. Guess how much sunlight there is at 9pm? Northern Europe ranged from 5pm to 7pm ... but in January in Denmark, solar insolation is very low.

...ignoring that virtually all have better building codes and much better insulation

By "virtually all", you really mean Western Europe. Excluding that, the rest of the world generally has much lower requirements than the US. And even in Western Europe, most of the difference in consumption isn't due to "building codes and insulation", but the fact that residences there tend to be much smaller, and much more likely to be multi-unit dwellings.

...power can and gets moved around, even actoss borders, and not always consumed where its made

And the further you move power, the more you lose of it. Today in the US, the majority of electricity is consumed within 150 miles of where its produced, and still we lose about 7% in total. Transmitting gigawatts 1000+ miles requires very expensive HVDC installations, and even still losses are high.

 

[Pawelr98]

From the original article from the first post:

For example, on the installation's 20th anniversary in 2012, the panels still cranked out 91.7 percent of their rated output.

The key part is rated. What is the rated power of a solar panel?
It's the power output of a solar panel given for 1000W/m2.

The problem with that is, that's a very generous, idealistic condition.
I studied automation at university, the part of the course was automation and control system for renewables.
For the overwhelming majority of the time, the solar irradiation is around 500W/m2. The ratings and data for ~1000W/m2 is fairly irrelevant as those conditions are very rare for most of locations.

I do recall from the lectures, a certain graph, PV efficiency over lifespan for different solar irradiation levels.
So including that 500W/m2 irrdation. While the efficiency loss for 1000W/m2 was fairly low, at maybe several percent (relative to original) over 10 years, the drop for 500W/m2 was far greater, at 30-35% iirc.
I was trying to find those studies, but for some damn reason, all the studies are for 1000W/m2, never mentioning lower solar irradiationlevels.
Unfortunately, those lecture materials were never provided to us, can't pinpoint any track of it, maybe if I was to visit the university again, I would be able to contact the professor that gave those lectures.
If anyone knows or has found such studies, I will be happy to read.

Then there's also storage, for the grid-level, each person can do their own math.
Calculate say diesel fuel sales to electric needs in transportation, propane needs to electric needs (you can use heat pumps "300% efficient" in the calculations) and then arrive at a final result, how much more power generation does the grid needs to replace all of those current fuels that are burned on-site to get heat or other things done?
For diesel alone I arrived at 60-80% ballpark increase in the electricity production to replace just the diesel fuel sales (I used very ungenerous numbers for the diesel vehicles too, heating oil sales not included).
Ballpark wise, not going to work out.
That's energy, not power. Storage will not fix this part of the equation. You need more production AND even more storage to keep the increasing peaks at bay now.

 

[Count von Schwalbe]

you can use heat pumps "300% efficient" in the calculations

I always use 260%, myself. Most heating COP values I see on datasheets are in that range.

how much more power generation does the grid needs to replace all of those current fuels that are burned on-site to get heat or other things done?

Our local energy producer (not utility) is TVA. They have a big electrification of heating push on, but they wouldn't be able to handle the increased load if everyone's heating went electric right now.

 

[Waldorf]

@Endymio
lots of assumptions on your part.
i have lived in multiple eurpean countries, mainly germany, so no, its not because of multi dwellings etc, and southern countries have oeak consumption in the evening becauze the usually dont work a few hours during the day, thus work/return home/eat late, no other reason.

never said anything about moving power needlessly too far, ignoring its again a problem with the US, not commo for others.

@Pawelr98
in recent years solar panels gotten a lot better, depending on use/cost taken i to account, iirc gains were around 50% vs previous.

 

[Endymio]

reserves are important as the multi-year drought in the US Southwest showed - Hoover dam kept the Colorado river flowing...

That brings a point that most today don't realize. From 1890 to 1970, the US built some 85,000 dams: essentially all of them primarily for flood control and irrigation, with power generation a secondary benefit. But since then, dam-building has been negative, with more removed than added. It's a non-reported, but still important factor in the flooding and water shortages of today.

I hear that some designs of Gen 4 reactors can load balance pretty well, in addition to the improvements in safety. One of them claims a 60% turndown in 12 minutes. Could be useful to balance out uneven solar loads.

The other problem with using nuclear to balance wind and solar is that nuclear's fuel costs are trivial: something like $.007 per kWh. So if you have the nuclear plant already, rather than run it at low loads to balance solar, it costs almost nothing more to run it full time, and skip the cost of the solar farm entirely: Nuclear-Costs-in-Context-2021.pdf (nei.org)

lots of assumptions on your part.
i have lived in multiple eurpean countries, mainly germany, so no, its not because of multi dwellings etc...

It's basic physics, not an "assumption". Smaller homes use less energy, and homes that share walls use less as well.

Germany.
Average dwelling size: 1,470 sq. ft.
% multi-family dwellings: 55%

USA:
Average dwelling size: 2,480 sq. ft.
% multi-family dwellings: 28%

...and southern countries have oeak consumption in the evening becauze the usually dont work a few hours during the day, thus work/return home/eat late, no other reason.

The "reason" doesn't matter, just the effect. When peak electric consumption doesn't align well with peak solar production, you have a serious problem. And again: it's not just southern countries. In Denmark, Poland, Germany, there is almost no sunlight at 5pm during winter.