A Solar Plant a Tortoise Could Love


On the Web site of GreenBiz.com, Mark Gunther describes Bill Gross as "a serial entrepreneur" and "one of the most interesting business people I've known." Gross is the guy who gave Google its paid-search idea. He likes robots. He has Google's money invested in his electric car project (only fair, right?). He also may be the guy to best solve the land wars that continue between desert conservationists and national environmental organizations over large-scale concentrating solar thermal power (CSP) in the desert.

Last week, Gross and the solar-power company he founded, eSolar, held a grand opening for a 5-megawatt plant called the Sierra SunTower near the California desert city of Lancaster, 70 miles from Los Angeles. It's the first of many such plants:  eSolar has contracts with Southern California Edison and NRG for hundreds of megawatts in CSP. What Gunther doesn't mention is that Gross is committed to doing it all in relatively small parcels on private, already disturbed land.

Here's what he told BNET.com's Chris Morrison last spring:

Of the $130 million we raised, we spent $30 million on land. We went and bought, specifically, previously disturbed farmland near transmission. So we don’t have to worry about wildlife migration patterns. We bought private land, so we don’t need special permission. Our 46 megawatt plant takes up  a quarter square mile, much smaller than other power tower plants. And one other benefit of going smaller is that the towers are smaller; that’s important for neighbors. If you’re above 180 feet, the FAA comes into play and neighbors may complain. We stayed lower than 180, around the height transmission towers are anyway. So we can locate much closer to the city.

I wanted to include eSolar in the story I wrote about distributed energy resources, but their public-relations person argued that the plants didn't really qualify as distributed generation. That's probably right -- 46 megawatts is a little on the high side for DG. But the same principles apply. CSP uses mirrors to focus the sun's energy on a liquid, which turns to steam and spins a turbine to produce electricity just like a coal plant does. It's cheaper than the photovoltaics we put on our roofs, which turn sunlight into electrons. But a 400-megawatt plant, like the ones BrightSource want to build in the Mojave Desert, will require clearing six-square miles of land -- much of it undisturbed public land conservationists have struggled to protect. Building it small, the way eSolar does, allows for building it close to the places it will power. And it allows eSolar to dodge a lot of trouble.

There are conservationists who will object to eSolar's plans as well, just as there are people who will continue to defend large-scale solar on public land. Both sides have their increasingly well-argued cases. But it's worthwhile to watch Gross plow ahead on his middle-ground solution while the other sides duke it out.


Sinjin Eberle
Sinjin Eberle
Aug 10, 2009 05:09 PM
Awesome times 234,000!!! This is the kind of innovation and smart thinking that hopefully can take hold. The energy guru's have been preaching distributed power (although this is bigger, as you said above) but on a practical scale, very well conceived. So many advantages to something like this it would be boring and preachy to list.

Lets just say...Awesome!
It's still a power plant
Doug Meyer
Doug Meyer
Aug 13, 2009 04:58 PM
Even when solar plants boil reclaimed water, the vast majority of them including eSolar’s, will condense the steam by evaporation. So you’re taking reclaimed water that would have recharged the aquifer and boiling it away instead. They could have built giant cooling towers to do it without evaporation, but that would cost a lot more while lowering the plant’s efficiency (because you’re cooling with hot desert air). Remember, these daytime-only power plants wouldn’t even be happening right now if solar companies weren’t getting huge, deficit-financed government help.

So the money’s gonna dry up faster than the aquifers, we’ll be nowhere near de-carbonizing energy supply, future generations will be left with the bill and a destroyed planet anyway, and as always, the land will be raped for somebody’s short-term profit. Oh, and I kinda doubt the tortoise will be impressed either. How about instead we start by admitting WE are the problem?
Judith Lewis
Judith Lewis
Aug 14, 2009 11:47 AM
I believe eSolar's SunTower uses reclaimed water in the condenser as well, not air, which is part of why it can generate more power on less land. The dry-cooled plants will have some trouble in the desert.

As for the daytime-only nature of the deal: The solar day, drawn on a graph, pretty much matches electricity demand. Nothing wrong with daytime only. In fact, it's what's driving system operators crazy about wind energy; there's no way to match the supply to peak demand.

You're right, though, it is still a power plant, designed to produce electricity. Seeing as how you typed in your comment on a computer, I'm assuming you still use some.
Solar Cooling Blues
Doug Meyer
Doug Meyer
Aug 14, 2009 01:33 PM
Yes, reclaimed water in the condenser, where it is then evaporated, which is a net loss of water from the local supply. You’re confirming my point. And yes, dry cooling in the hot desert would make the plants much more expensive to build AND considerably less efficient. That’s why the capitalists are not doing it. They’re in business to make money, not to worry about whether they’re using water sustainably. But even a progressive like Michael Hogan, Power Programme Director for the European Climate Foundation, sees the problem:

“In the desert areas where CSP will thrive, the consumption of large amounts of water by conventional wet cooling systems is clearly unsustainable. Dry cooling alternatives will be required, and CSP will have to demonstrate its commercial viability despite the capital cost and performance penalties this will entail.”

My point about solar being (not quite perfectly timed) peak power, is one of scale. Since we can’t afford even these few plants, why should we build them if even a lot of them wouldn’t be enough to juice our 24hr energy-consumptive economy? Good luck explaining your side to the tortoise.

And yes, as soon as I stop seeing progressive cheerleading coming from so called “environmental journalists”, an abdication of journalistic responsibility that reminds me of the lead-up to the Iraq war, (then and now ultimately driven by our energy consuming way of life) I’ll gladly go back outside and just chill in the summer shade.
PV instead of solar-thermal
Jim Dodson
Jim Dodson
Aug 19, 2009 12:49 PM
Recycled waste water is better than water out of the domestic supply (don't want to get into the "toilet-to-tap" debate about trying to get communities to accept waste water in any guise) but this all helps to encourage the photovoltaic alternative, which has minimal water use. Several of these are also on the planning boards for the Antelope Valley using the same dispersed siting as eSolar. Check out NextLight at Fairmont Butte in the western end of the valley.
PV or CSP - Both Have Impacts
Nolan Patrick Veesart
Nolan Patrick Veesart
Aug 19, 2009 03:41 PM
In the desert, water is in short supply. Indeed, that is how we define "deserts". If reclaimed water is not being used to recharge depleted supplies, then there is less water available for people and wildlife. To people who live in non-deserts, it may seem silly to quibble over such seemingly small amounts of water, but in the desert, where many plants and animals have evolved to live on tiny amounts of water, every drop counts.

Energy production has impacts. Period. PV panels may use less water than CSP, but they cover more ground. It is a fallacy to think that private lands somehow have less biological value than public lands. In general, with few exceptions, public lands are the lands that were left over after all the high-value lands were taken and privatized for profit. In any event, the energy industry now wants to cover both private and public lands with industrial solar facilities and the wildlife be damned.

I fail to see how it is responsible to "solve" one problem while creating or exacerbating another. I am less interested in meeting the needs of the investor owned utilities than I am in preserving what little natural land we have left. There are other options. It starts with conservation and ends with distributed, small-scale energy production - preferably in urbanized areas as close to where the power is to be consumed as possible. Don't tell me that it can't be done. It can. The biggest obstacles are the utlities that oppose it (for obvious reasons), some big environmental groups which, inexplicably, back the utilities, and journalists that fail to fully cover the issues, ask the hard questions, and keep the public and the decision makers informed.

I'm not trying to offend anybody here - we can all do better - but I am trying to be heard in the roar surrounding the rush to so-called renewables. There is a right way to do it, and a wrong way. I don't think we have too many chances left to keep doing things the wrong way.
Solar / Wind farms
Lise Pettijohn
Lise Pettijohn
Sep 06, 2009 10:07 AM
Nolan, your comments are right on! I live in the Arizona high desert and now we are confronted with landowner / investor / developer plans to install co-located wind turbines and CSP on over 54 square miles of beautiful high desert environment. This is only Navajo county, even bigger plans exist for Apache County. And..they wish to draw State and BLM land into this plan to increase the already massive size.
I have vastly reduced my carbon footprint over the years and I live off the grid, using solar PV and wind for electricity generation. I live a very conservative energy use lifestyle, having given up clothes dryer, dish washer, television (no loss there..) and innumerable electronic gadgets. I am outraged that our fragile environment is poised to be destroyed by huge utility scale installations. Right next to quiet rural communities and homesteads. Also the plans are to use wet cooled CPS, thus putting another giant industrial straw into the Coconino aquifer. It is outrageous, another example of corporate profit and bottom line winning out over people, wildlife, environment and proper stewarship of our precious water resource. We have started a grass roots community organizing effort to mitigate this insanity, please wish us luck!! - Lise