Solar PV: no longer “the energy of the future and always will be”

This is kind of a big deal. Almost 40 years now since the design of the classic No Thanks logo….

1) The average capacity factor for fixed-angle PV installations is usually worse than 25%. California solar had a 16.4% capacity factor in 2009 according to EIA data. That said, the trend is indeed encouraging for solar and discouraging for nuclear. Since the first European Pressurized Reactor installations started in France and Finland, both have had mammoth delays and cost overruns. Even if solar isn’t expected to be cheaper than nuclear on average, solar projects may be more palatable because their costs and scheduling are more predictable. There’s a virtuous feedback cycle: more solar projects get built because they are low risk and they become lower risk because more get built (more historical data to estimate from). And of course the smallest projects don’t even need coordinated financial arrangements; a small residential solar system can be in the low 4 figures range, while even “small” nuclear reactors are hoped to be in the mid 8 figures range. Actually-being-built nuclear reactors are all in the 9 figures range.

2) The National Renewable Energy Laboratory estimates that the US could generate about 800 terawatt hours per year (roughly 20% of current US electricity consumption, roughly equivalent to current US nuclear output) from solar panels placed on existing rooftop space. That estimate is based on 13.5% efficient panels. There are already commercial panels based on plain old silicon that can do better than 20%. The US could generate a tremendous amount of PV energy without developing any new land, relying on any unproven technological advances, or discovering any new sources of rare elements like indium and tellurium.

3) The big sticking point is storage. Right now there is no inexpensive way to save electricity generated during the daytime peak for use at other times. At low intermittent-renewable penetration this is unimportant but it will become important as the renewable share grows. It is already a problem in Hawaii, which relies on expensive diesel fuel for most of its electricity and has seen solar installations soar recently. The utility companies can’t accept more than 15-20% renewable capacity on the grid without destabilizing it. Electricity storage is the next great renewable challenge now that PV generation has established favorable cost trends and multi-gigawatt scale.

4) Pure-electric and plugin hybrid vehicles could be an excellent complementary technology to stabilize grids in the presence of high intermittent-renewable production. Keep more production near point of generation for charging car batteries. In the case of necessarily grid-linked renewable generation, like wind farms or utility scale solar, electric vehicles can still serve a stabilizing role by matching demand to production through smart grids. This is a mirror image of the historical practice of matching production to demand.

5) Substituting renewable electricity for fossil fuels has an earlier, more favorable cost parity point when it goes up against liquid vehicle fuels instead of coal or natural gas. The Nissan Leaf consumes 200 watt hours per kilometer traveled, on average. According to Solarbuzz, current solar PV costs in sunny climates are from 15 to 29 cents per kilowatt hour, depending on the size of the installation (industrial to residential). That means the Leaf consumes 3 to 5.8 cents of sunny-climate-PV-electricity per kilometer traveled. A Nissan Sentra will consume 6.8 cents of gasoline per kilometer traveled (12.75 kilometers per liter, 87 cents per liter of gasoline). That’s based on current average US gasoline prices. If you live somewhere where liquid fuel costs more (like the US West Coast, Hawaii, or most of the rest of the developed world) then the savings are greater.

Of course, the US MSRP of a Leaf is $19,000 more than that of a Sentra — ouch! At current US gas prices you’d have to drive 500,000 kilometers on low-cost PV energy to make up the initial sticker price difference. If you were paying Perth, Australia prices of ~ $1.60 per liter, it would still take nearly 200,000 kilometers to reach break-even. But in a few years you can expect that PV will cost even less and gas will cost even more.

6) The environmental benefit as well as the economic benefit is also higher if renewable electricity displaces motor fuels instead of conventional grid tied generation. Small internal combustion engines are less efficient at using fossil fuels than utility scale power plants and their combustion emissions cannot be scrubbed as effectively.

7) The energy security benefit is also higher if renewable energy displaces motor fuels instead of conventional grid tied generation. The US currently imports about half of its oil consumption but only a tiny fraction of its coal consumption. By far the dominant use of oil in the US is for car and truck transportation. If the US oil consumption per capita could be brought down to the average level found in the EU, the US would actually be a net oil exporter and eliminate more than half of its annual trade deficit (more than $250 billion).

In 2007 the PV that powered my uncle’s well in Arivaca finally died. They had been manufactured in 1979 so their death was not unexpected. What was unexpected was how extremely expensive buying new PV panels was in 2007. I believe my uncle replaced the two small PV panels at a cost of $3000 a piece or $6000. At those prices the only way that the market could expand at all was to greatly reduce prices.

“Takeing Quiggins Australian pov for a second, there seems to be more than enough coastline close to the population centers to get by with a wind heavy mix, while weather conditions for solar energy are only perfect far north from the population centers.”

(North? Don’t you mean west/north-west?)

P.S. Tropical areas may have stronger sunshine, but it is less seasonal. That is both an advantage and a disadvantage – so I’m not sure quite what you mean by “ideal”.

Very cool and heartening article. At the risk of going slightly OT do you have any similar info on pebble bed nuclear reactors? From what I’ve read they seem to have enormous potential both as a power source and as an acceptable means of electricity generation for environmentalists and industry alike.

Count me in as one of the pro-nuke leftoids who is reconsidering. I’m not there yet, because nukes remain the only currently existing baseline power source that does not contribute to global warming. But I’m beginning to wonder if the ever-escalating fixed costs of nukes are beginning to swamp the very low marginal costs (costs calculated both environmentally and monetarily.)
One of the open questions in my mind is to what extent coal, if used as baseline (or backup) power in a mostly-renewable economy, will continue to drive global warming. Or whether a fully-renewable economy is medium-term feasible (e.g., energy storage through pumping water or practicable superconducting long-range transmission lines or fuel cells that can drive a real-world car.)

“fuel cells that can drive a real-world car.”

We can do that already. Just not a price that anyone is willing to pay.

There’s no theoretical reason at all why they aren’t possible. I’m sure they will be made too, at prices people will pay. It’s just there’s another decade or two of fumbling around in the manufacturing process to get the production cost down.

“One of the open questions in my mind is to what extent coal, if used as baseline (or backup) power in a mostly-renewable economy, will continue to drive global warming.”

Coal’s cheap, but the capital cost of a pulverized coal plant is about $3,500/kW compared to $800-1000/kW for a natural gas combined-cycle plant. So cheap natural gas (e.g. from fracking) will tend to stop coal plants from being built, as the rationale for building more coal plants is the volatility of natural gas prices. You’ll still see coal plants being built where natural gas is expensive or there’s a geopolitical concern about security of gas supplies.

What you may see more of is more coal bed methane, which (in my mind) is going to be prone to unmeasured and unmonitored (and hence uncosted) CO2 and methane emissions, especially where they’re using chemical and biological treatments to get more methane. There’s also a technology called Underground Coal Gasification, but that’s still in the pre-commercial stage.

Cheaper cells won’t entirely solve the problems with solar: you still need the ancillary costs of inverting DC to AC for transmission (or domestic use), and energy storage. At the moment, solar thermal is still cheaper than solar PV, and solar thermal is more amenable to overcoming the intermittency of solar energy (because you can store the thermal energy in a heated material and then tap it later on.)

Also, there’s still concern on the stability of the grid with distributed power.

But agreed, the fact that Solyndra went Tango Ultra because solar cells got too cheap was actually *good news* that the MSM didn’t pick up on.

A diagram of U.S. Energy use is given here:

http://lawprofessors.typepad.com/environmental_law/2011/12/the-2010-us-energy-use-flowchart-.html

Total energy use is 98 quadrillion BTUs (aka quads). Energy from solar is a barely perceptible yellow line at the top of the diagram, ~0.1 quads.

A useful measure of energy (instead of hard to envision exajoules or quads) is “The Cubic Mile of Oil” [http://www.amazon.com/Cubic-Mile-Oil-Realities-Averting/dp/0195325540]. Currently, the world’s energy consumption is equivalent to 3 cubic miles of oil per annum. Useful for putting technologies into perspective.

There’s little point in debating nuclear power. After Fukushima, it’s politically dead, dead, dead, no matter what one’s theoretical attitude to it might be.

The site variability of solar is a lot less than for wind. I saw a claim (I don’t have the data to back it up), that claimed the max site difference in the USA was only a factor of two. They were comparing a site in Arizona with one of the Washington coast. Wind varies very substantially, and doesn’t scale downwards in turbine size well. Intermittencywise a mix of solar and wind is better than using either method alone.

The nearterm constraints on PV penetration are islanding (turning off the distributed generation during an outage), and less predictable generation swings, like happens during a partly cloudy day. Predictable production/load changes, such as sundown can be handled with natural gas plants. I expect intermittency will be handled with a combination of storage, demand management, and wide area transmission, rather than by a single method.

Total energy use is 98 quadrillion BTUs (aka quads). Energy from solar is a barely perceptible yellow line at the top of the diagram, ~0.1 quads.

A useful measure of energy (instead of hard to envision exajoules or quads) is “The Cubic Mile of Oil” [http://www.amazon.com/Cubic-Mile-Oil-Realities-Averting/dp/0195325540]. Currently, the world’s energy consumption is equivalent to 3 cubic miles of oil per annum. Useful for putting technologies into perspective.

The present scale of energy use is indeed daunting. However, it is also worth considering the concrete consumption by source and technology mix rather than reducing everything to one standard of joules or oil-equivalents.

By way of example, my earlier Nissan Leaf vs. Nissan Sentra comparison: the Leaf consumes 0.72 megajoules (200 watt hours) of electricity per kilometer traveled, on average. The Sentra consumes 2.75 megajoules of gasoline per kilometer traveled (gasoline: 35 megajoules/liter, fuel economy: 12.75 km/liter), on average. The Leaf goes 3.8 times further on the same number of megajoules.

Processes that consume energy to perform computation, emit electromagnetic radiation (including visible light), do mechanical work, or regulate temperature (at least in the range of a few tens of Celsius from ambient) are much more systemically efficient when the primary energy source is renewable electricity rather than fossil fuels*. Fossil fuel combustion to directly produce mechanical work, low-grade heat, or light is very inefficient. Even in the best case more than half of the energy is wasted as heat, and 2/3 waste is more common. The balance improves if you can find additional useful work for the waste heat, like district heating from your fossil fuel power plant.

Fossil fuels do better at making full use of their energetic potential when they are used to manufacture chemicals or provide high-grade heat. Producing methanol starting from natural gas consumes much less primary energy than producing it starting from renewable electricity, water, and carbon dioxide. Producing cement from limestone using fossil fueled kilns consumes little, if any, more primary energy than producing it in electric furnaces, and coal/natural gas are certainly cheaper than electricity.

The good news for the future is that energy needs for present society are weighted toward the former sort of work, where renewable electricity can “punch above its weight” by doing the job with fewer primary energy megajoules. This includes all surface transportation, all agricultural and industrial processes that involve pumping, drilling, crushing, grinding, rolling, digging, welding, and cutting, all lighting, ordinary refrigeration and freezing, data centers, computers, and consumer electronics, and all building climate control excepting some very cold regions. 3 quads of coal might be replaced by 1 quad of renewable electricity, depending on the end-uses that coal was supporting.

Building climate control and water heating is a major energy consumer that has the potential for thermal-solar to punch even further above its weight. Low grade thermal energy — exactly what you need to keep buildings comfortable — can be extracted from sunlight at lower cost and higher efficiency than electricity production. This has much more potential for new buildings than for existing ones, though. It’s probably too expensive/disruptive to re-engineer existing buildings to take full advantage of passive and low-cost solar climate control.

*Strictly speaking, the “primary” energy source for wind, hydroelectric power, solar PV, and coal alike is the sun. If you divide the total energy produced by hydroelectricity by the total solar energy input driving precipitation cycles in a watershed, it’s abysmal. But of course the efficiency of fossil fuels is worse yet if you trace it back to millions of years of prehistoric sunlight. Practically speaking it makes sense to treat the electricity produced by solar/hydro/wind as their primary energy and to treat the heating value of fossil and nuclear fuels as their primary energy.

Capitalism is far too messy and far too dependent on failure as a regulatory mechanism to be safely used for a nuclear industry.

I love this. I am adopting it whenever I discuss nuclear power, especially in the USA. ‘dependant on failure as a regulatory mechanism’. <3

What does this price drop mean for the levelized cost of solar PV (JQ’s article gives the old price per kWh, but what is it now)? The other link states that the module cost is 35-40% of the total installed cost of PV. So if PV was around $0.50 per kWh before the price drop (which is typically the number I’ve seen), this will get it down to what, $0.35-0.40 per kWh? That’s still several times more expensive than fossil fuels and even wind.

Add in the fact, as noted above, that solar PV is a trivial amount of power generated currently, and it still has a long way to go. Wind has rapidly grown from a trival amount of power in 2000 to about 3% of total power in the US (about half of hydro), and it has been working through growing pains associated with dispatch and integration, supply of turbines, NIMBYism, wildlife impacts, health impacts etc. I think a lot of those concerns (outside the dispatch problem) are overstated, but don’t expect anti-renewable advocates to go quietly into that good night. Once solar hits a sizable portion of total generation, I expect there will be similar rows over externalities (real and made-up) associated with production and disposal of panels, dispatch, etc.

So while this great news (especially for off-grid applications), I wouldn’t take a solar victory lap quite yet.

“I don’t get the people who dismiss Fukushima with ‘it was externally caused’. What, you’re ok with massive radiation leaks so long as they were externally caused? ”

Because I get less nervous about nuclear incidents caused by external events than those caused by lack of following Standard Operating Procedures and made worse by inherent design flaws (like the RMBK reactors which operate in a metastable equilibrium). In the same way that we see the driver in a traffic fatality caused by slipping on black ice less culpable than one caused by a driver texting or with a glass of Jim Beam in his hand.

And because nuclear accidents scare me much less than the potential of a 7 C warming by 2300. Which I saw in some climates projections at a conference a few weeks back.

“However, it is also worth considering the concrete consumption by source and technology mix rather than reducing everything to one standard of joules or oil-equivalents.”

AFAIK the authors of the “One Cubic Mile of Oil” factor the thermodynamic efficiencies in.

However, solar thermal has greater thermodynamic efficiencies (because it’s a heat cycle with a lower delta-T than most fossil-fueled heat cycles), and if solar PV’s thermodynamic efficiencies are miserable compared to any heat engine. So I’m not sure what your point is, here.

The only advantages I can see to a large-scale switch to electric cars are (1) recovery of energy from regenerative braking and (2) CO2 emissions from electric generation are point-source and so you could do carbon capture and sequestration. You’re just displacing the emissions.

If you can’t scale up renewables, and a glance at the diagram shows how far renewables have to go, and new nuke plants are off the table, a switch to electric cars is just displacing the emissions. Fukushima will do more damage environmentally because of its stalling of new nuclear plants than the primary damage from the radiation leak.

“One argument for electric cars is that they are inherently more efficient than ICE engines, i.e. calculating emissions from well to wheel”

Depends on the efficiency of the underlying electrical source, whether it’s coal or natural gas.

A lot of the well-to-wheel estimates for electrical cars assume Natural Gas Combined-Cycle as the source of the electricity. A state of the art NGCC plant with the latest spiffy high-temperature gas turbine from Siemens or GE gets up to 60-62% thermodynamic efficiency. Add to the lower carbon intensity of methane than petroleum, and yep, electric cars look better than hybrids or straight internal combustion.

It’s different if coal’s the electricity source. A supercritical pulverized coal (PC) plant has an efficiency of 30-35%. Add to the higher carbon intensity per joule of coal compared to liquid petroleum fuels, and things look worse for electrics than for IC engines and hybrids.

At the moment, there’s a lot more electricity supplied by PC than NGCC. It’s all where you draw the envelope for your analysis. An additional complication is when the electricity is generated – if you’re charging at night and there’s a nuke or hydro or wind plant supplying the off-peak electricity, then things look better.

Again, I see the advantage of electric vehicles as turning mobile CO2 sources into static CO2 point sources, at which point we can Do Something with the CO2 emissions, like shoving them into a saline aquifer. That’s if CO2 sequestration doesn’t turn out to be a busted flush like first- and second-generation biofuels have turned out to be.

“The cost reduction [sufficient for solar to achieve grid parity] seems like a pretty safe bet over the next 5-10 years” – John@38

A very optimistic prediction. Yes, we have had a sharp price drop in the last 5 years – that doesn’t mean we will have a similar one in the next five. I think it is far more likely the recent price drops were a one-off step change as China geared up, rather than establishing a new trend. Absent some exciting *fully developed* cost-saving semiconductor technology waiting to be implemented (do you know of any?) then I’d expect that we’ll just see a modest further reduction over the next decade as we asymptote towards what is possible with manufacturing existing designs.

Plus, of course, people are right to point out that the cost of the panels is not the sole factor limiting very large scale PV use. In the long run I reckon nuclear – hopefully better than we currently have, and certainly far better than we had with Fukushima – is still a good bet, despite its very real drawbacks.

The downside, is that if you make the assumption I do, that any barrel of oil saved by doing X, will be consumed by someone else doing Y, then you’ve just increased the number of cars that a fixed amount of oil can support, increasing net emissions in the meanwhile.

That’s why in my opinion, the big energy efficiency savings (in the US at least) will have to come from a redesign of urban planning and infrastructure that drastically reduces vehicle miles traveled per capita. Other high-tech countries already have much lower VMT/c while maintaining equal or better overall quality of life compared to the US, because their development is designed to allow people to take better advantage of mass transit and because they don’t systematically underfund (a) urban governments in general and (b) mass transit systems in particular.

“Globally, the IEA estimates “Fossil fuels currently receive USD 312 billion (2009) in consumption subsidies, versus USD 57 billion (2009) for renewable energy (IEA, 2010g)”

Fossil fuels supply about 375 Exajoules, and renewables, including biomass, about 70 Exajoules. Eyeballing those numbers and those from the IEA, it looks like on a per joule basis are subsided to about the same level. But even compared to other fossil fuels, coal is cheap on a per million BTU basis.

As for the Aussie subsidies: my limited experience with the convoluted ownership structures and shell games Aussie energy investors use has convinced me that if I ever had such an investor over for dinner, I’d count the silver afterwards.

Sock Puppet of the Great Satan, you’ve got that right; that kind of investor would not only trouser the spoons, he’d leave you a bill for your own food.

By contrast, there is no apparent path to a solution based on nuclear power. I argue at my own blog that the only option with even a remote possibility of making a substantial contribution by 2030 is the AP1000, and even that’s a long shot

http://johnquiggin.com/2012/01/03/the-nuclear-option-ap1000-or-bust/
Have you looked at South Korea? Korea plans to bring about 14 GW online domestically until 2021 (and has recently affirmed they will continue on that path), partially current designs alread under construction, partially their evolved APR-1400 design. And they are also building 4 of the new design in the UAE for another 6 GW by 2020. That brings them to your 20GW by 2020 on currently affirmed plans alone.

To continue Tim’s argument. A lot of the supply chain development is fed or starved based upon the demand -and future expectations of demand, for the end product. Economists, or techologists like to sweep all of this complexity into the concepts like learning-curve, economies of scale, and Moore’s law type empirical fits. Of course few industries are an island in themselves, many technological advances are imported from unrelated industries, and vice versa, so changing the scale of one industries cash flow (say Silicon PV) doesn’t change the funds available for all useful subcomponents by the same factor.

One example, is floating offshore wind, importing marine platform expertise and manufacturing from off shore oil drilling.

SPGS (19)
“geothermal, except in a few areas, is cost-prohibitive because of drilling costs”

Funny thing, the oil industry doesn’t appear to have been inhibited by drilling costs.

Tim Worstall – continuing development runs at its own speed, perhaps influenced a little by demand and FiTs…

Omega Centauri – To continue Tim’s argument. A lot of the supply chain development is fed or starved based upon the demand, and future expectations of demand, for the end product. Economists, or techologists like to sweep all of this complexity into the concepts like learning curve, economies of scale, and Moore’s law type empirical fits.

If only some way could be found of directly channeling resources into this kind of research so as to rouse it from its torpor, rather than relying on the oblique and apparently rather ineffectual method of prodding and tweaking Market Forces.

It’s conceivable that we could find experts who are interested in solving these issues, and give them control of substantial funding, rather than hoping some get-even-richer-quick merchant will take a punt. As a side-benefit of putting such experts in control, we’d have found a respectable referent for the term ‘technocrat’.

Obviously we can’t do that really, because it might stifle ‘entrepreneurial activity’, which would be a crying shame. The Invisible Hand processes of the market are, like natural selection -a cruel, wasteful, aimless and agonisingly slow random walk- spontaneous, and that is the really important thing where -ideological appeals to high Tory sentiment- industrial production is concerned.

Tim @56.
Even if we didn’t have ideological blinders preventing us from having a largescale industrial policy, the experience of my many coworkers who used to work at government research labs, is that they become stiflingly dominated by internal politicking. Various medium level and above managers start building and protecting empires. And because the nature of the work and its potential is so difficult for the managerial class to assess, inevitably spin and PR end up dominating the future direction of research determining process. I doubt it would work very well.

Various medium level and above managers start building and protecting empires remind me, we’re talking about large organisations in the public sector are we?

Thing is, as with solar cells, efficiency is not really a concern per se, or rather there is no particular level of inefficiency that would make proceeding not worth bothering. (There is no real shortage of sunlight, nor in the circumstances much of a constraint on available funds or personnel for research, I should think). It’s output we’re interested in. And mpowell beats me to pointing out that there are already organisations full of scientists ready to conduct research projects if funds are made available (I find it odd to think of them as ‘private’ but I suppose in the US many of them pretty unambiguously are.)

“It’s conceivable that we could find experts who are interested in solving these issues, and give them control of substantial funding, rather than hoping some get-even-richer-quick merchant will take a punt. As a side-benefit of putting such experts in control, we’d have found a respectable referent for the term ‘technocrat’.”

Hey, count me in. I’ve got 5 applications in at present anyway. Would love one or more of them to come off.

Tim @60.
I used to think much like your comment, that efficiency doesn’t matter, just raw cost per watt of capacity. But, I’m largely changing my mind. I think we can both agree that for a site with enough available area, and a fixed need, that the figure of merit is (annualized) output per unit of cost. But, I think not all applications and sites fit that billing. Also we need to consider the cost of the entire system, not just the cells or panels. Most of the BOS costs are proportional to area, so clearly a more efficient panel even with a higher cost per nameplate watt, may be able to recoup that disadvantage once the cost of the entire system is considered.

Then, the biggest growth area for PV, in the US at least, is utility scale plants -not residential rooftops. These are typically rated in the tens to hundreds of megawatts, and the land requirements are substantial, as well as the political battles related to the use of that much land. Consider that to replace a 1GW reactor, with PV at say 10% efficiency requires 50 square kilometers, (assuming a 20% capacity factor). Thats a pretty hefty amount of land. Higher efficiency can greatly cut into the needed size. Currently there are battles going on concerning the construction of large scale PV in the Antelope valley near LA. Obviously a decrease in acres needed per megawatt would be a big help.

TW. Actually we agree about the need for publicly directed research/development -even “subsidies”. A lot of would be things that require technological/industrial development have serious chicken and egg type problems. The barrier to becoming commercially viable can be too steep for the private market to tackle.

“One should never forget that civilian nuclear power increases the spread of nuclear weapons. ”

Oh balls. Not all fuel cycles do, plus there’s the work on thorium plants.

“Carbon Dioxide Capture from the Air Using a Polyamine Based Regenerable Solid Adsorbent”

OK, here’s the problem: the less concentrated the CO2, the more thermodynamic work to capture it with a material and then regenerate it. So while it’s good to have these capture co2 fom the air ideas, it’s far from the ideal option. Capturing CO2 from the air makes solar look cheap. Unless you’re using plants.