JDG, solar is NOT a cheaper way to provide peaker energy.
Say you build a solar farm. XCel comes to you and asks for a quote to provide 0-100 hours of peak energy each year, with an average of 25 hours, at their demand with a 5 second response time and 99.9% reliability factor. If you quote would 7 cents per kWh you'll go bankrupt. $7/kWh, maybe.
That's how the cost of these natural gas peakers is calculated. The comparison is a joke.
David, extend your concept of "economic analysis" beyond the vague bogeyman of "line and transformer losses". Large solar farms are cheaper than rooftop. CPS gets a volume discount on their large systems and collects tax subsidies. This lowers their cost to the point at which they can feed PV kWhs into the grid and not lose much money, or maybe make a little. Even after line and transformer losses eat a few percent of the output.
When a customer installs rooftop PV, the customer gets the tax subsidy. Not CPS. Then CPS pays full retail for kWhs the customer generates, getting no revenue to offset the costs of being the customer's "battery". The economics are simple - ratepayers without PV carry the load for those with PV. It's de minimis when only a few people have PV, but becomes unworkable as rooftop penetration grows.
Let's say every CPS customer bought enough rooftop to net-meter to zero kWhs. CPS revenue would go to zero. Who would pay for the grid? Who would pay for all the kWhs CPS must generate at night and during cloudy spells to give those net-metered customers the 24x7 service they demand?
Keith is correct. PV can only be an insignificant feel-good story with current net-metering schemes. For PV to succeed on a large scale utilities must adopt rational net-metering price schedules.
Anon, primary zinc-air cells have been sold for ages, but Eos and several other companies now have rechargeable designs. Your comments on the subject are outdated and misleading.
Getting back to CSP-thermal, I agree it has an uphill battle. You get the most kWhs from your investment in mirrors and motors with a 40%+ multi-junction PV cell at the focal point. At 15-30% efficiency, thermal systems deliver much less bang for the buck. Thermal systems also have more maintenance and reliability issues than PV. Thermal's only advantage is cheap storage, but that's not an issue until solar's market share grows at least tenfold from current levels. And even then there are other ways to address the issue.
Ice-Bear type systems effectively store off-peak electricity in thermal form for daytime cooling. In strong cooling climates they could also help with renewable intermittency. Buildings with very high thermal mass can also help with both load leveling and intermittency. But seasonal thermal storage is a different matter. Ground-source heat pumps do this in a way, but the thermal storage is passive in nature. I'd need a lot of convincing to believe active thermal storage can work on a seasonal basis.
This article misuses the term LCOE. $2.29/W looks like straight capital cost, perhaps adjusted somehow. LCOE is levelized cost of electricity and is almost always expressed in cents/kWh. I'd guess these systems come in around $0.15/kWh LCOE.
Also, Amonix won't achieve the cost declines quoted ($2.95/W to 2.29/W to 1.30-1.40/W) through efficiency alone. These gains also require cost reductions in materials and labor. Such reductions are possible as the technology improves, but that should be noted in the article.
Why do people buy homes in HOA areas, sign the HOA covenants agreeing to abide by the rules, then cry and whine when the HOA enforces those rules? If you don't want to live under the convenant restrictions attached to house title then don't buy that house.
There are plenty of houses without HOA restrictions. Of course this means your neighbor might build a henhouse complete with rooster crowing at 4am or pull a few single-wides onto his property to generate rental income, but you will be free to add all the PV panels you wish.
This isn't a blanket defense of HOAs, some of which are power-mad. But it's a thousand times easier for a reasonable individual to get a bad HOA rule changed than a bad federal law. This is what jl-mar doesn't get - conservatives and libertarians aren't anarchists who oppose all government. They just loathe massive bureaucracies run by professional politicians on the take from unions and big business. HOA is the smallest unit of government, with very limited powers and whose members join voluntarily. That's the opposite end of the spectrum from "big government".
Is Fresno really a good PV site? Lots of sun in the summer but I seem to recall dense winter fogs that last for the better part of a month.
'more people are working in the US on solar energy than coal mining'
You act like this is a good thing. It's most definitely not, especially considering coal delivers so much more of our energy than solar. The goal is to meet our energy needs with the LEAST amount of labor. Heck, if our main goal was to 'maximize jobs' we'd just go back to farming by hand.
This article shows that coal is still way, way ahead of solar on this key metric. The good news is solar has made progress, the bad news is it still has a long way to go.
Thom, you are right. Coal labor hours, which mostly produce present-day kWhs, are different than solar labor hours, which mostly produce future kWhs. Proper analysis matches each labor hour with the kWhs it produces, discounting out-years for time value. LCOE is one such approach, and it shows the gap is not nearly so wide. But there's still a gap. Especially if you include the labor needed to build and operate storage and/or backup systems, grid connectivity and so on.
Are solar kWhs worth more than coal kWhs, justifying the higher labor cost? That's entirely subjective. Some value solar's cleanliness while others prefer coal's reliability. We can advance solar by changing minds, or we can continue to make solar more labor-efficient. Ideally we'll do both, but IMHO the latter leads to better results over time (and greases the skids for the former).
Anyway, my argument with this article is the wrong-headed focus on 'jobs'. It's pure politician-speak. I cringe every time a politician talks about how many jobs he's 'created'. Heck, politicians could end our unemployment problem today by hiring 5 million people to dig ditches all day and another 5 million to fill them in at night. Real-life political jobs programs contribute no more to society, they just hide their uselessness better. The way forward for solar is to keep figuring out how to generate more kWhs with fewer jobs. A single-minded focus on employing the most possible people leads to bad places.
Editor - the Baltimore Gas & Electric system is open-loop. Having customer A/C units sent response data back to the utility would "close the loop".
Batteries and other "brute force" storage systems are rarely cost effective. There are smarter ways to go. Demand response is virtually free with a smart grid, which we need anyway. EVs and PHEVs could be a massive source of 'dispatchable demand' (even without V2G, which has issues). As noted above, thermal storage can be a huge winner. The Ice Bear system, for example, is very cool (ha):
"....each gigajoule of heat produced using switchgrass pellets would cost $21.36. Using fuel oil to produce the same amount of heat would cost $28.22."
A gigajoule of NG costs about $4. Most people switched away from ultra-expensive heating oil years ago. The rest would like to but are trapped by even higher switching costs. If pellets can reduce those switching costs then terrific. It's a small market but every little bit helps.