Eric Wesoff
Real Solar Thermal at Intersolar July 18, 2008 at 1:02 PM
I moderated a solar thermal panel at Intersolar on Wednesday with three major players in the rapidly emerging solar thermal market – Ausra’s Glen Davis, Acciona’s Gilbert Cohen and Josef Eichhamer of Solar Millennium.
All of the firms that were on the panel have major contracts to provide power, are building or have built numerous power projects already, and – in the case of Acciona and Solar Millennium – have years of real power generation experience with massive scale solar thermal power plants. These are not naïve startups with hopes of sales but active and successful providers of utility-scale power. All of the participants on this panel used variations of a mirrored-trough style architecture.
Ausra’s Glen Davis discussed the significant differences in financing solar thermal projects versus financing wind projects.
Here’s a quick rundown of Glen’s major points:
Acciona’s Gilbert Cohen may have more experience in solar thermal projects than anyone on this planet, which is why we were fortunate that he was able to give us a summary of the real world performance of a project he has seen through from start to finish – the 64-megawatt Nevada Solar One. Here are some photos and videos of the project.
Neva
da Solar One cost $266 million to build and at $3,700 per megawatt installed represents the lowest cost per watt of any solar thermal project to date. Mr. Cohen sees this price plummeting even further as more experience is amassed and as supply chains become more mature. The plant is producing reliable power right now (if you’re reading this in the daytime) and is actually producing 11 percent more power than predicted. This level of brilliant success will pave the way for more solar thermal projects with confident, motivated financiers.
Nevada Solar One (pictured on the right) is producing power today.
We also heard from Josef Eichhamer of Solar Millennium who extolled the virtues of incorporating molten salt storage into a solar thermal system. The addition of a Thermal Energy Storage system can add up to seven hours of dispatchable power to a plant profile. This does a lot to dispel any notion of renewable energy being unpredictable. Eichhammer said, “This is firm power, not intermittent.”
Some fun salt facts: TES’s plant uses 27,500 tons of salt. It’s tanks are 14 meters high and 38 meters in diameter. The salt (KNO3) costs about $1,600 per ton.
TES allows utilities to meet peak demand with solar power even if the sun is not out. This is especially important in Spain where many of these projects are being built, as Spain has a unique power profile with a peak at midnight!
Massive storage tanks for molten salt Thermal Energy Storage (TES) at the Andasol project can be seen in this image.
Solar thermal power with thermal storage is here today and with no fuel risks and no carbon footprint should grow faster than anyone has predicted.
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A good read. And a nice recap on what I prefer to called CSP - concentrated solar energy. It correctly notes that a big advantage of CSP over PV (photo voltaic) solar is that diffuse sunlight can be ‘concentrated’ many times to a single source.
But probably the biggest advantage CSP has is its ability to store energy (heat in this case) which tames the intermittent nature of this renewable.
If the Achilles heel about renewable power sources like solar and wind is its intermittency, then CSP’s ability to store potential electricity as heat is a very big advantage.
Think about it. The world’s hitherto most successful renewable, which has been around for a century or so, is hydroelectric power. All that water backed up in a reservoir behind a dam is also stored energy.
I would point out, however, the chart above needs updating. Storage is also coming to wind power. Flywheels provide short term spinning reserve capabilities and flow batteries cover long term needs.
Indeed, VRB Power will be installing a 2MW x 6hr system at the Sorne Hill Wind Farm in County Donegal, Ireland. An independent group, Sustainable Energy Ireland (SEI) found that the addition of “storage” essentially increased the IRR of the wind farm to over 18% in a industry where IRRs of 7% to 9% are considered their norm.
Lux Reseach recently issued a report called storage “the next big thing.”
One thing is for certain, storage changes the game for renewables.
[...] spoke about molten salt thermal storage at a panel I moderated at Intersolar and I blogged about it here. The company is building molten salt storage on a massive scale. It is a proven, reliable, [...]