Rooftop Solar May Reach Grid Parity In 25+ States By 2017
In just three years, new numbers tell us, more than half of the states in the US may have rooftop solar available at the same price as the local grid’s electric rates. And that’s even without considering state and local incentives!
The Cambridge-based Union of Concerned Scientists has just published a series of three quick infographics. Here’s what they show:
- By 2017, more than half the states could have rooftop solar as cheap as local electricity prices.
- Installing rooftop solar has never been more affordable.
- The number of households with rooftop solar is skyrocketing.
Rather than claiming copyright privileges, the UCSUSA encourages the media to pass these graphics along, so here they are. More information is available at this link.
You’ll find a full description of the methodology used by the UCSUSA here in PDF format, including all source and forecast data. Assumptions are also clearly stated, and links are provided to full-size files. The Washington, DC, information graphics consulting and services Graphicacy produced the infographics.
Have a tip for CleanTechnica? Want to advertise? Want to suggest a guest for our CleanTech Talk podcast? Contact us here.
Our Latest EVObsession Video
CleanTechnica uses affiliate links. See our policy here.
One very important thing when the solar leasing company is not showing you in their “savings” comparison chart is that the price of solar panels could go down further, putting you in a bind for expensive and escalating payments. Funny thing is that the solar leasing company never pass on to their customers, the lowered production cost of electricity from the cheaper panels.
I don’t understand. Is it not the case that when you sign the lease your cost if fixed? Why would future panel price declines escalate your payments?
Future panel prices are irrelevant as you suggest. But many solar leases do have escalating payments that go up over time. They do this to be no-money-down and start with a low payment.
you did not get it. consider the alternative of saving money so that you can buy the panels later compared to leasing now.
then you need to include money you lost by not taking advantage of cheap solar and good incentives today.
Had a presentation from a Solar City representative at our place in San Tan Valley,AZ, Their lease price is fixed over the term of the lease
you’d be way better off saving the money to buy the panels because it would be at a lot lower price in the future. with a lease, you’re it, a prisoner of your contract and you would have lost real money.
If the lease is less than you would have otherwise paid to for electricity then you will have saved money.
If owning is a better deal then you will save more money.
Either way you aren’t losing money. You’re paying less than you would have had you done nothing.
Yes, costs will likely continue to drop. But that true for a lot of things. A some point one has to say “good enough” and commit.
I have been waiting until solar panel efficiency is high enough, and batteries are good enough that I can supply 100% of my power needs with solar — go off the grid. This is not so easy as I have a small roof and live in an area with high heating requirements… but the house is superinsulated, so it’s not that far away from reality. A 10% improvement might be enough.
I can’t think of a way you can supply 100% of your power needs with solar for less than a fortune.
Unless you happen to live in one of the sunniest places in the world. In that case it would only require a large amount of money.
I’ve been off the grid for about 25 years, just sayin’ I’ve got some experience.
Best to be a gypsy solar panel wagon, going from town to town. Buying low, selling high to keep the budget balanced.
Or take a working vacation to a cheap island manufacturer of the panels for the best price?.
So we’re saying solar panel buyers are a homogenous lot?
In other words, there is way too little data about where this solar powered spaceship is headed in our lifetime.
Zack’s research work here is amazing but the public is fickle.
One way to look at it is that solar energy will be good investment only when the annual price reduction of the solar system will be smaller then an earning on an alternative investment.
Annual solar price reduction < Annual return on an alternative investment
In a somewhat strange way, the fast reduction of solar system price make investment in solar system unfavorable.
One should really use return on a fixed rate instrument.
OK, I get it solar is getting cheaper and cheaper and I’m happy about that, but the sun doesn’t shine 24 hour a day. What I want to know is where will the cost of batteries have to be for people to go off grid and especially how many KWH of batteries would an average american home need to get to go off the grid, who can supply this info with a source?
It appears that for some time, even average American homes that deploy solar panels, will continue to use the grid – as their storage battery.
No, residential solar users do NOT use the grid as a “storage battery”.
They use the grid to buy electricity from commercial generators when they need it (just like any other electricity consumer), and to sell electricity to other consumers when they are generating more than they need (just like any other electricity generator).
Virtual battery.
Basically, the amount of batteries you need depends on your NIGHTTIME electricity usage, which very few people measure. This is usually mostly heating or A/C. This usage can be vastly reduced by a superinsulated retrofit, which is quite cheap.
Battery costs should drop about 50% in the next few years. It won’t be cheaper than grid in Illinois for a while, but it will be cheaper in Hawaii (where grid power costs a fortune).
I dig what you’re saying, but just remember — There is no more constant, consistent, on-time, plentiful, renewable and cheap fuel as the sun.
Also, you’re not likely to go off grid just because you go solar.
For those of us in northern climes, there isn’t enough sun in the winter to store up for when the sun goes down. I have a solar installation but when winter days are only eight hours long, I need the grid to keep the lights on at night. I also happen to use electricity for heating which makes the problem worse.
In most cases it’s going to make sense to stay connected to the grid. Give yourself access to cheap wind and hydro when the Sun isn’t shining. Share your excess solar with people who have none.
Sure . . . but stay connected to the grid and take advantage of wind power and hydropower in the winter.
Check out the artcle just a few steps up about micro-grids. While it may not be possible for an individual home to go completely off-grid, it is usually possible to pool together generation and storage at the local community level.
That is why it is a good idea to have a grid, and combine solar energy, wind energy, hydro energy, peak power plants, storage, and demand side management
Step one: switch to LED lights. They use about 10% of the electricity of incandescents and last for 10 years.
Step two: superinsulate your house (see the “Superinsulated Retrofit Book” from 1981, or call an installer who knows about the German Passivhaus standards). It’ll cut your heating load to about 10% of what a typical poorly insulated house uses.
Step three: go back and calculate what your nighttime electrical load is NOW.
There are some articles on this site that kick that question around.
Go to the site search box on this page and put it “battery storage”.
In general, if you live in a place with “normal” electricity costs then storing your own electricity at this point in time doesn’t make financial sense. If you live in a very expensive market such as Hawaii then the math could work.
Thanks for the search tip, I had not seen that.
If it only “could” work in Hawaii, then I guess we’re very far from it. So another question would be, if 100% of power could come from solar and wind, how much would it cost to keep the grid and all of the back up power sources running. How much would this add to electricity cost for each kWh? Any articles regarding this?
First, our coal and nuclear plants are getting old and aging out. We’re extending the life of some of our reactors, but this is not cheap. In sort, we are going to be spending money for new capacity regardless of what we choose.
Now, new nuclear (with subsidies) is at least 11 cents per kWh and requires some storage. New coal (if were were to build any) would be even more expensive.
New wind is now about 4 cents per kWh, and should fall further. New solar is in the 7 to 9 cent per kWh range and falling rapidly. These are subsidy free prices.
We’re years away from needing serious amounts of storage. We’ve got some interesting, and potentially cheap, new storage methods being tested. And we know we can store with pump-up hydro or flow batteries in the 5 to 8 cent per kWh range.
Let’s try some math using nuclear-friendly numbers:
Assume 40% electricity direct from 4c wind. 30% directly from 8c solar. 30% from stored 6c wind/solar and stored at 8c.
That’s 8.2 cents per kWh. Cheaper than 11 cent nuclear.
One study I’ve seen on this matter says that it’s our cheapest option:
http://cleantechnica.com/2012/12/11/wind-solar-storage-could-power-full-electric-grid-cost-effectively-99-9-of-the-time-by-2030-report/
http://cleantechnica.com/2012/10/02/95-renewable-energy-world-possible-by-2050-with-no-technology-breakthroughs/
More such pieces here: http://cleantechnica.com/70-80-99-9-100-renewables-study-central/
Boris, great question! When, if ever, will it be possible economically to be off grid in the city or suburbs? Since I am off grid for 14 years and having to do it economically and for a residence that usually has 15 people with all modern conveniences of food storage and washing machines and computers and lights and well pumps etc etc. I know it can already be done. But there are a few considerations…electric heat is not yet possible. Everything else is. The main tipping point is not pv solar but the cost of batteries. That is teetering on the edge of being truly affordable. See our discussions of New lithium battery banks..it is a discussion in progress, not completely clear yet.
You will never be able to be off-grid in an apartment building… though you could have a microgrid just within the building, I suppose. Still, you won’t have enough roof area in a big apartment building to go off-grid.
We’ve hit the point where solar is cheaper FOR THE UTILITY COMPANIES than building coal or nuclear or natural gas plants, so solar is going to take over very fast regardless of whether you go off grid.
Batteries can double the price of your solar PV system and they are generally not worth it unless it is a remote off-grid cabin. Grid-tied is better/cheaper for most.
If you are talking about large amounts of energy on a grid scale, you might want to use power to gas:
http://en.wikipedia.org/wiki/Power_to_gas
Storing energy from renewable s in hydrocarbons allows a very high amount of energy to be stored.
Via your link, electricity -> gas -> electricity efficiency is pretty low. 30% to 44%.
Flow batteries and PuHS efficiency ranges from 65% to 95%.
For large amounts of energy, batteries become unattractive considering cost. Even with the lower conversion efficiency.
Some improvements under-way for the gas -> electricity efficiency is using high temperature fuel cells.
Although using power to gas is at first sight counter-intuitive, analysing the costs show it can be very cost competitive compared to alternatives, even with the lower efficiency.
Vanadium redox flow batteries. 65% to 75% efficient. Probably 8 cents or less per kWh. Able to store large amounts of energy for long periods of time in rather simple tanks.
PuHS which would be in the 85% to 95% efficiency range. And the kWh cost between 5 and 8 cents. Want more capacity? Make the reservoirs larger.
The choice (assuming that others don’t appear) will come down to math. And infrastructure will be a large part. Infrastructure and efficiency. If one method loses more than 50% of the input then it’s going to have to come to the game with much lower infrastructure cost.
Batteries with their efficiency from 65% – 75% and power to gas with
Electricity → Gas → Electricity
Hydrogen 34–44 %
Methane (SNG) 30–38 %
Minimal difference in favor of power to gas (using Vanadium redox flow batteries as reference for batteries) is 65% – 44% = 21%.
If energy needs to be stored for months (seasonal storarge for northern latitudes) drop a few percentage points in battery efficiency.
If high temperature fuel cells would be used efficiency could increase to reduce this difference. (efficiency combined cycle 60%, high temperature fuel cell(60%) combined with combined cycle 60% Would get 84% back to electricity conversion instead of 60%)
Calculating the new efficiencies:
Using electricity -> gas efficiency:
Hydrogen 54–72 %
Methane (SNG) 49–64 %
200 bar compression
New electricity -> gas -> electricity efficiency:
hydrogen 45-60 %
Methane (SNG) 41–53,76 %
200 bar compression
The infrastructure costs are very cheap, cost effective as I told you already.
Existing methane gas network already have storage capacity, thus can be used without new investments. There is no extra material cost per kWh. Scaling this cost up makes batteries less attractive the larger the energy storage needs get.
“Batteries … 65% – 75%”
“Hydrogen 34–44 %”
“Minimal difference in favor of power to gas (using Vanadium redox flow batteries as reference for batteries) is 65% – 44% = 21%”
Are we having an honest discussion when one cherry picks the highest number for one alternative and the lowest for the other?
A very tiny percentage of solar owners are off grid. The norm is to stay connected to the grid.
The ridiculously low estimate of 900,000 solar homes in 2020 comes from our old dinosaur friends at the EIA. In this case, it’s the higher estimate that is solidly based on historic cost trends. The baseline Q3 2013 mean residential cost is still $4.5/watt, against the German mean (from BSW) of €1.64/w or $2.19: not far from what SolarCity is paying now. So a substantial further fall in US costs can be expected without any progress in technology or module prices at all.
PS: the picture is more dramatic if you look at the whole world. Comparatively. the USA has very low retail electricity prices and high residential solar installation prices (though not utility). So it’s behind the curve, not ahead of it. Suntech’s Stuart Wenham claimed in May 2013 that 102 countries were already at grid (socket) parity (link), the great majority of the world’s countries and population.
Thanks for making this point.
My self-installed system is ridiculously nice. I pay nothing for electricity, I pay nothing for gasoline (since I have an EV), and the utility writes me a check because I still generate more than I use. Time reduce my natural gas usage now.
You rock. 😀 CleanTechnica gold. 😀
retail power in tx is <10 cents/kwh. there is no way you are at net parity w/o subsidies. ah yes, and we have no net metering,