Brad Ideas - Are Solar Panels a wasteful way to go green? - Comments

Solar panels and energy conservation

B Harris — Fri, 31 Jul 2009 15:12:16 -0700

Brad - Thanks for the very well thought out explanation of the true costs on Solar Panels. I find many articles touting School Districts and higher education campuses employing “Solar” as their product of choice to cut energy costs. These decisions are presumably made by intelligent, well informed people, so I am confused. Why it is that a person of authority would choose solar when clearly it is not the best use of their limitied funds?

I say this because my husband’s company recently expanded its consulting services to Schools Districts to include energy efficient products and services to help with the budgetary contstraints they are experiencing. The goal is to cut their energy usage and costs to free funds up for other "Educational" needs.

My husband looked at Solar but ended with the same thoughts as you in that Solar was not the way to go. He found a manufacture who, along with many other pros, provides the only UL Listed LED T8 replacement tubes in Northern America. Different models range in consumptive power from 10 - 22 Watts for the same amount of luminance as the standard 32 - 40 Watt 4’ fluorescent tubes currently used in most classrooms around the country.

They have calculator that, in its simplistic and conservative version, indicates a savings of up to 70% of energy costs with an average ROI of 3 - 5 years and an approx lamp life of 11 years. Because these claims are proven, he and I believe this is the quickest and most efficient way to save energy and costs for our schools. We are however, receiving much resistance from the districts and believe it is because of the newness of the technology. Do you have any input on this type of LED lighting and/or can you tell me smart people are making dumb choices by choosing Solar over LED?

Yes, can be useful

brad — Mon, 23 Mar 2009 00:12:58 -0700

In that the greatest heat matches the time of solar availability.

The key thing to realize is that solar panels only work properly if you use every joule they generate. The more you throw away because batteries can’t take it (or because they are in shade or not pointed right) the less productive they are, and since they are not super productive it’s easy to fall off the cliff.

Depends on Where you Live

Dave — Sun, 22 Mar 2009 23:36:53 -0700

Just for the record - Toyota never claimed that the solar panels on the car would do anything but cool the interior on hot days. A panel the size of your car roof will generate 100-200w at most. Assuming the upper end of that and you parked in the direct sun for 8 hours, that would only produce enough power to move your car 2-5 miles.

That said - If you've ever lived in an area where your car will bake in the sun, having a solar powered fan that keeps interior car temps near ambient temps instead of 150*F+ is worth it's weight in gold. Especially if you have young kids and are worried about their safety and well being climbing into hot car seats on a summer day.

Keeping the car's interior cool will also significantly reduce the load on the A/C. It can take 10-15 minutes of 100% A/C to cool the interior of a car sitting in the sun to comfortable levels. Doing so takes a lot of extra power.

So a solar car roof may not be as green as it appears, it's certainly useful.

That's very odd

brad — Sun, 22 Mar 2009 23:31:00 -0700

It looks like the sheet was set by accident as publicly writable, and somebody changed it. Sorry about that.

CFL Quality

Dave — Sun, 22 Mar 2009 23:26:22 -0700

The biggest problems with CFLs is that most of them are crap.

Most of them have horrible warm-up time, color, etc.

A few of them are good.

I'm not the best judge of color quality, but at least in terms of warm up time which is annoying for any light which isn't on for long periods of time, the best bulbs I've bought are made by Feit Electric. I've gotten a couple different bulbs made by them and they've all been instant on (just a fraction of a delay before the starter kicks the lights on). I'd judge the initial light output to be 80-90% or barely discernible from 100% light output.

Ones that have long warmup times:

Ikea. These were enclosed bulbs with some textured glass. Look nice, but poor light output and slow warmup.
n:Vision. Got these from Home Depot. Slow warmup. Widely varying initial light output across the 4-6 bulbs I got. Work fine once warmed up, but takes a while to do so.

Would be nice to collect more input to help people avoid crappy CFLs. They give CFLs a bad name.

Prius Calculation Corrections

Dave — Sun, 22 Mar 2009 23:17:23 -0700

The Prius calculations are totally wrong.

Your average car will last 9-10 years before being junked. It said 3.
Your average call will be driven close to 15,000 miles/year. It said 5000.
Your average Prius nets 46mpg. It said 42mpg.
You claim that the non-hybrid averages 30mpg. The most fuel efficient non-hybrid family sedan I could find was the Hyndai Elantra which averages 28mpg. You have to get a compact car to average 30mpg in a non-hybrid. (See fueleconomy.gov)

Anyway I've corrected the numbers. Still doesn't appear to be quite as good as some of the other options, but obviously how "good" it is depends on a lot of factors.

Getting rid of it

brad — Sat, 21 Mar 2009 17:42:59 -0700

Yes, I fully agree, you can’t just give them a certificate for a new fridge. You need to do it through a company (who would gladly oblige) who delivers and picks up the old fridge.

I would go further. To facilitate this, I would start a program that told manufacturers of fridges that they had to install a watt-meter in the fridge to get with the program. This is not that expensive. The new owner could see the kwh. The watt meter would be programmed to, knowing the efficiency ratings of the fridge that was replaced, display how much power this one used compared to the other one and how many dollars it saved the owner. It would know when the door was open and closed, cooling used etc.

If you did this, you could even have the new owner pay back the donor of the new fridge with half their energy savings.

For example, we find a poor family with a fridge from 1980. Plenty of those out there. We give them the new fridge. It saves them $100 per year in electricity. We require them to send $50 of that to us. The meter in the fridge tells how much. If they don’t send it, we come repo the fridge. They have to believe that the meter is correct and the figures for their old one are correct, and they have to understand this is not costing them money. They have to understand their power bill went down $100 and they paid $50 of it out.

Another way to do this would be to forget the meters and work on averages. The power company would collect the $50 by adding it to the power bill, and remit it to the fridge donor. So they would get a power bill that was $50 less than before — and a free new fridge — and the donor would get a $50 cheque for 20 years that pays for most of the money they donated to buy the fridge. And middlemen skim amounts to grease all this.

Are CFLs competing on their own?

Ethan Lipman — Sat, 21 Mar 2009 17:27:59 -0700

I've purchased CFLs a while back when they weren't cheaper than incandescent

I've also purchased them years later and found the boxes featuring the local power utility's logo advertising that the bulb's price was subsidized by our friendly local forward looking utility company.

I've seen huge billboards advertising the twisty bulbs encouraging people to look past the new perhaps weird look, and adopt the more energy efficient bulb.

I've heard news of banning the sale of incandescent http://en.wikipedia.org/wiki/Banning_of_incandescent_lightbulbs

Seems to me CFLs had a huge marketing problem: They look weird (though it didn't bother me.. many ppl had aesthetic concerns)
They weren't cheap: Prices have come down a lot (not sure if gov't or utilities are involved in that still, but they certainly have been)... even though they might last forever compared to incandescent, people don't see the benefit of something that makes it's money back over time and has a big up front payment.
They don't even work as well: people expect light to come on at full power right when they flick the switch. That doesn't happen with many CFLs, and some of them buzz...

So.. Gov't banned incandescent, utilities subsidized CFL prices and erected billboards advertising for their usage.

Perhaps these gov't actions were totally appropriate considering the decrease in energy usage..

Or maybe I could make the argument that the technology should be perfect: no buzzing and it had better turn on instantly at full power when I flip the switch, and until CFLs can do that, government should be investing in CFL and LED R&D, not funding the adoption of a current flawed technology that needs to be subsidized and have the existing incandescent options banned from the market place before it can compete..

If I'm not mistaken, this response to the energy crisis
http://apps1.eere.energy.gov/state_energy_program/case_study_detail_info...
was really a response to Enron's shenanigans.

Not so easy to prove you wrong :-(

Ethan Lipman — Sat, 21 Mar 2009 17:01:04 -0700

Brad,

I was really hoping I'd have an easier time proving you at least partially wrong!
I've worked for two years for a Solar Power integrator designing and permitting PV systems for residential and commercial applications. Work consumes much of my time and energy, but I'd like to at least tell myself it's for a worthy cause!

I felt like you were a bit too quick in dismissing my argument that future improvement and product cost reduction if a function of the success of existing products on the market.

Do you think the level of venture capital investment in clean tech would have been the the same over the last few years if nobody was buying and installing the current products on the market? If Google had not done this - http://www.suntechenergysolutions.com/google_video.html, if nobody was installing on their rooftops, and the multi-MW farms in Europe and all the rooftop PV in Japan did not exist, do you think investors would have the same confidence and willingness to invest in the next generation of products?

I do not have any analysis to show you about the true environmental cost of disposing a fridge. I do however think that somebody should win a nobel prize if they can figure out how to recalibrate the global economy to properly attribute a realistic cost to throwing stuff away. I was living in San Diego for the last three years where they have free trash pickup.... absolutely zero fees to throw stuff away, and zero incentive to minimize waste. Mind boggling in its social irresponsibility. It's long been considered political suicide to change.. but perhaps hell is about to freeze over: http://www.nbcsandiego.com/news/local/Will-San-Diego-Dump-Free-Trash-Col...

Both of these links confirm what I said about most people moving the old efficient fridge to their garage thus increasing their energy consumption when they buy a new one, so your fridge distribution plan would definitely need to pry the old one from their wall socket.
http://blog.mlive.com/businessinnovation/2008/09/that_old_refrigerator_i...
http://www.reuters.com/article/pressRelease/idUS200506+30-Sep-2008+BW200...

-Ethan

Just a thought, Brad. When

Anonymous — Sat, 21 Mar 2009 12:27:40 -0700

Just a thought, Brad. When everything goes electric maybe it will become mandatory to plug a vehicle into a socket where one is available so excess current could feed back into the system?

Even if they had connected it

brad — Sat, 21 Mar 2009 12:18:12 -0700

The value of a solar panel on a car is quite dubious. For proper performance a solar panel is aimed at the sun. If stationary, that means at least pointed south and tilted to your latitude. A horizontal panel is not nearly as good, and one that will likely often be parked in shade even worse than that.

Further, the normal goal of a Prius is to have the battery be charged when you stop, so you can start electric. But once the battery is charged, the solar panel’s energy is thrown away, except on things like the cooling described. You could perhaps tell the Prius “I’m going to park you in the sun in 5 miles so stop charging the battery with gasoline so the solar panel will have a chance” but will people do that and will they do it reliably?

solar panels are great, but not on cars

Peter Fairley — Sat, 21 Mar 2009 06:54:10 -0700

I've done some reporting on the questionable value of photovoltaics mounted on cars, including the optional solar roof to be offered on Toyota's 2010 Prius. See Toyota's Underwhelming Solar Prius

No, it's $75K

brad — Thu, 19 Mar 2009 19:30:30 -0700

It’s $75K because you spent $40K and various forced convinced the government to kick in $35K because of the (arguably mistaken) belief that solar panels are the right thing to subsidize to green our electrical load.

There is $75K to spend (it doesn’t matter from where) and we want it to cause the most possible reduction in grid load. What is the way to do that? It’s clear that replacing lighting is the biggest winner I can see so far. Replacing fridges is also good. Putting in solar panels, in comparison, is very poor.

It has nothing to do with charity.

As to when you break even, right now solar never breaks even at the national average grid price, even with the big government assist. Tell me your numbers (grid price, grid price increase assumption, kwh generated per year by your system, rebates and tax credits, current mortgage interest rate) and we can work out when your system breaks even, if ever. Right now the typical solar cost is about 22 cents/kwh without the rebates, I believe, which is of course never pays for itself because it is much more than typical grid. With rebates I’ve seen it get down to 12-15 cents which almost breaks even. In California with the tiers, both these numbers can break even, so long as you don’t put on so much solar that you don’t even fill up tier 1.

However, again, and this seems to be hard to make clear, it doesn’t matter when any of the technologies “break even.” If a technology saves 1 MWH, then it returns a benefit to you of about $100 at typical retail prices, $40-$50 at typical wholesale prices. However, other than the retail/wholesale distinction, it doesn’t matter, because everything that saves a megawatt returns the same savings. It’s what it costs to generate that which matters. You can say that anything which returns more than it costs is justifiable, but what if you can do twice as much with the same investment of time and money?

Charity and Solar

Dave Michels — Thu, 19 Mar 2009 16:53:12 -0700

You are confusing charity with a reasonable investment in solar power.

I understand charity - and contribute to various groups or causes that I wish to support. Sometimes they even send me a bumper sticker or canvas bag - but that isn't what drives the contribution. I am as happy as the next guy to give my time or money to important causes.

The errors are that you keep looking at the total cost. Using our combined figures above - I didn't give or donate or pay $75k, I paid $40k. You can't compare the $40k to $75k in fridges. So now we are at $40k of fridges which is still a noble deed. Of course, you didn't consider the environmental costs involved in manufacturing those fridges or the fuel and pollution associated with transporting them or even the landfill impact of tossing the old ones, but why would you? That would be an academic exercise that misses the point.

So we are at $40k. The Government presented me a deal that said if I spend $40k, they will give me an additional $35k in value. That is pretty compelling. If I get enough deals like that, I really could buy a bunch of fridge's for donation. But on top of that - I get an asset that increases the value of my home (hard to say how much, but yes as with almost all home improvements it will depreciate (appliances, carpet, windows, etc.). Plus I get 80% of my electricity rebated to me and since electricity prices are more likely to increase than decrease - the value of the rebate will also increase. So it really isn't $40k at all but much less. I don't recall the official ROI which was based on these and other factors, but probably around 12 years. I know it was based on modest 5% price increases in electricity, but I expect higher - so let's call it an even 10.

So if I break even at 10 years or so, and they have a 25 year lifespan - that means that not only will they contribute to society as a whole with pollution-free energy production for 25 years, but they will actually earn me money after a decade.

So My $40k investment actually has an environmental impact and a personal ROI. The fridge's have an environmental impact and arguably a social ROI - but that's what my charitable contributions (and taxes) are for. The government also offered me a tax incentive to buy a Hummer last year, which I declined. It didn't align with my personal goals and objectives.

Hindsight is always 20/20 - in this case, I can honestly say that my $35k would have completely disappeared, and not turned into fridges or panels at all - because all of my stocks crashed.

I was also indirectly involved with a project to put solar panels up on a local humane society. The project was funded 100% by charitable contribution. These panels are also "green" and attracted donors interested in being green - but not only does the environment win, but it will re-allocate $1000 a year from utilities to animal care which is their mission. It is nice to be able to be successful in a mission and help out the environment.

When to buy Solar

brad — Thu, 19 Mar 2009 12:14:00 -0700

No, I’m with Martin from Nanosolar. He’s right. Put your money into pushing conservation and cost-effective green power (thermal-solar, wind, geothermal, skylighting) instead of into PV panels. PV panels are going to get cheaper.

And no, I don’t think that people buying them when they are not cost effective helps prove the market for cost effective panels in the future. Well, it does to some degree, because it measures how much bias people will have towards panels when all other things eventually become equal. But is demonstrating that love a good way to use such large sums of money? Surely if people were putting money into funding wind farms or solar thermal plants or buying new fridges for their neighbours, the investment community would have no doubt that these people would jump at solar panels once the panels were a more cost effective way to reach the goal.

We should put our money and time where it should do the most good. That is the thesis here. Do you disagree with that? Do you really think PV panels are where it does the most good?

I should put LEDs on the list though today they are actually a fair bit more costly than CFL. I am happy to add all sorts of things to the list. As for conservation vs. green generation: While the believers will do conservation for the sake of conservation, the public doesn’t. You have to show the public why it’s in their direct financial interest. A light bulb that produces the same amount of light and lasts longer is in their interest. A nice new fridge with a lower power bill is in their interest. Sacrifices they don’t like, and convincing people to do sacrifices is a much harder path to success. Focus on what works best now until you can’t get returns from it, then go onto the next level. I believe generation is essential because of this.

Yes, we should fix the wall warts. On other sections of this blog I have long articles about the need for a universal DC power system which, among other things, would be more efficient as you would get one power supply running everything on your desk, or even have one in your house.

Yes, recycling that fridge has costs. If you have analysis that shows it is more expensive to recycle than keep running, let me know!

The fact that coal and gas don’t pay for their externalities doesn’t alter this thesis at all. All the methods outlined — PV, wind, conservation — all factor against the same grid. If grid power is made more expensive, it does bring solar down to being competitive with it, but it makes the other methods even more competitive. The base cost/MWH of offsetting grid power does not alter with the cost of grid power. Only the net cost. I should make it clearer in the spreadsheet but the net cost is essentially always $110 less than the bulk cost when working in the home (at an 11 cent grid rate) and lower if you are a power plant selling the power at a wholesale rate.

Once again, the thesis is simple.

We should focus our money on time on those methods that produce the most energy offset for the dollar
Solar isn’t even close to being near the top of that list

Which do you disagree with?

Are Solar Panels a wasteful way to go green?

brad — Mon, 16 Mar 2009 15:39:41 -0700

Last week I wrote about what I consider the main goal of green electricity efforts, namely to stop burning coal. You can do that, to some extent, by removing demand from the grid in places where the grid is coal-heavy. Even in other places, removing demand from the grid will be fairly effective at reducing the production of greenhouse gases.

Update: Since this article a flood of cheap solar panels from China has been changing some of the economics discussed here. I have not altered the article but some of its conclusions deserve adjustment.

No matter what you do — conserve, or put up solar or wind — your goal is to take power off the grid. Many people however, consciously or unconsciously take a different goal — they want to feel that they are doing the green thing. They want their electricity to be clean. This is actually a dangerous idea, I believe. Electrons are electrons. In terms of reducing emissions, you get the exact same result if you put a solar panel on your house than if you put it on your neighbour’s house. You even get a better result if you put it on a house that’s powered by a coal plant, so long as you also reap the benefit (in dollars) of the electricity it makes.

People don’t like to accept this, but it’s much better to put a wind turbine somewhere windy than on your own house. Much better to put a solar panel somewhere sunny than on your own house. And much better in all cases if the power you offset is generated by more by coal than at your house.

However, the real consequences are much deeper. The following numbers reveal it is generally a bad idea to put up solar panels at all, at least right now. That’s because, as you will see below, solar panels are a terrible way to spend money and time to make greener electricity. Absolutely dreadful. Their only attribute is making you feel good because they are on your roof. But you should not feel good, because you could (in theory, and I believe with not much work in practice) have made the planet much greener by using the money you spent on the panels in other ways.

The true goal is to find the method that provides the most bang per buck in removing load from the dirty grid.

Keep reading to see the math and a spreadsheet with some very surprising numbers about what techniques do that the best.