Big solar, little solar - Page 2

Which renewable technology holds the key for a sunnier (and more democratic) energy future?

Desert solar farms like the Ivanpah facility (above) need miles of transmission lines. Rooftop solar panels (below) don't.

Rooftop solar has gained traction in California over the past five years with a $3 billion program to subsidize installations. The California Public Utilities Commission recently touted the California Solar Initiative (CSI) program's success — a 47 percent growth in installations since 2009. All told, the Golden State boasts 924 megawatts of solar generation capability, installed at 94,891 locations. Consultants for the California Public Utilities Commission found that 11,543 megawatts of solar could be generated on large urban rooftops statewide, while another 27,000 megawatts could be generated on empty lots near rural substations.

The potential is huge, but a cost barrier remains. Even with incentives, residential solar remains largely inaccessible to people who aren't rich enough to own property or finance the upfront cost. In San Francisco — recently declared the greenest city in North America by Siemens — roughly 70 percent of residents are renters who almost never have the option of going solar. Proponents of desert solar farms claim that the large-scale, centralized technology offers something that rooftop panels can't — the potential to bring renewable energy to the masses.

The largest desert solar plant under construction worldwide is BrightSource's Ivanpah plant, which Bechtel is building in the Mojave Desert. Spearheaded by an Oakland company, the plant uses sunlight and mirrors to generate steam to power a turbine. The energy will flow onto the grid to serve PG&E and Southern California Edison customers. It's a dramatic improvement compared with burning coal, but there are other issues. On a yearly basis, it will use enough groundwater in the arid desert to cover 100 acres, one-foot deep. And it riled environmentalists who worried that it would affect the habitat of an endangered tortoise.

No one disputes that on a per-watt basis, it's cheaper to install desert solar than rooftop solar. According to estimates from Go Solar California, it costs more than $8 per watt to install small-scale rooftop solar systems, while recent costs for desert solar farms have been calculated at around $4 per watt. "Because they have the economy of scale, they can be built at less cost," notes John White, executive director of the Sacramento-based Center for Energy Efficiency and Renewable Technologies.

Yet a renewable energy expert who formerly worked for the California Energy Commission (CEC) says comparing costs of desert and rooftop solar from the point of view of the customer tells a different story. In April, Sanford Miller delivered a presentation at UC Davis that could have been considered subversive. His analysis essentially found that ratepayers shell out less to subsidize rooftop solar installations than they do to finance the purchase of energy from desert solar farms once the full cost of transmission and environmental mitigation are factored in.

"From a ratepayers' perspective, rooftop solar would be significantly cheaper than the desert solar," Miller says. When he sent his findings around to his colleagues at the CEC, "no one disputed it," he said. "But the view was that desert solar was inevitable."

But that still leaves the question of who can afford solar — and this is where Tom Price, former executive director of Black Rock Solar and now part of a solar investment firm called CleanPath, believes he's found a middle way. As things stand, every utility customer chips in to subsidize the cost of individualized solar panels for the lucky few who are installing them, he points out, and those same customers are footing the bill for energy companies to buy power from giant solar farms. He's pushing the Community Solar Gardens bill as an alternative.


True that ‘large scale solar is attracting billions in investment’. But only because the government has promised these profits through massive ARRA grants (free money), and risk-free (read low cost) loans guaranteed by the government. The companies investing are motivated by profit and profit alone, and they would not otherwise be interested.
Then, as you point out, roof-top solar essentially competes with utility companies for generation and distribution of electricity. Knowing this you can understand why the utility companies don’t like roof-top solar.
Several entrepreneurial companies here in California have found a solution for homeowners who can’t provide the up-front investment to put solar on the roof. These companies pay for the installation, lease the equipment to the homeowner who then pays a monthly fee to the solar company. The net is a lower total bill.
The net of all this is that the government has picked a technical solution -- big solar in the desert. Being fundamentally political, governments are not good at engineering. A government’s job is to create an economic environment that will let entrepreneurs figure the best way to do something.
Meantime, we are grievously wounding our western open space heritage, like a spendthrift heir running through an inherited fortune. We will all be poorer for this, economically and socially.
And by the way, it is looking more and more like photovoltaic is becoming the dominant big-solar technology, mainly for cost reasons. This will leave Ivanpah, committed to steam and turbines, a dinosaur in the desert.

Posted by Budlong on Jul. 14, 2011 @ 10:44 am

Bill Gates may have an expertise in computer operating systems and building a mega-corporation, but he has no expertise in alternative energy or in problem solving outside of his field, and without his big money his opinion would not get any attention. Two cents is a fair estimate of its worth.

Second, government officials always support big projects. Big projects mean they accomplish big things (whether good or bad). More importantly, it involves big money (taxpayer money). A politician who steers money to a corporation will get a percentage of the money back either in campaign contributions from the corporation, or by becoming a highly paid lobbyist or member of the board of directors of the corp. after leaving elected office. It is important to understand this.

Readers who want and unbiased and well documented discussion of alternative energy can go to: or read Community Power at

Posted by justfacts on Jul. 15, 2011 @ 2:10 pm

The Obama Administration has turned out to be one of the historically worst administrations for protecting the environment. They are making precedent setting policy that is rolling back 40 years of environmental protection. They have fast tracked big solar developments taking up to 5 to 6 square miles of desert at a time, much of it in critical wildlife habitat. They are turning out to be very good republicans.

If you examine the current situation regarding solar applications on public lands, you will notice that all of the big solar applications on desert land that are I under review now are for large 6 to 7 square mile photovoltaic (solar panels) facilities. The concentrated thermal plants (big mirrors) are white elephants and the federal money they need is gone. Photovoltaic plants are cheaper to build, but are still much more expensive than conventional power sources.

If you are using solar energy to be "green", it is utterly stupid to put these panels out there on tortoise habitat when all of the rooftops in Las Vegas have nothing on them! They could have just as easily pumped stimulus money into a feed in tarrif. Solar panels don't care if they are on you roof or in wildlife habitat.

What is very sad is that most of the environmental organizations have sold out the southwest desert habitats. A whole coalition of them are promoting a bunch of Solar Energy Study Zones being reviewed by the Feds. The end result will end up being about half a million acres of public lands that will end up having a one step approval for big developers to clear land and build millions of photovoltaic panels in pace of tortoise habitat. (they will just dig up the tortoises and move them). Why wouldn't environmental groups want these developments in disturbed areas first?

Posted by BighornNV on Jul. 16, 2011 @ 8:20 am

@BighornNV: how do you know that or in other words, are there any public site with these informations? would be great to provide the source, thanks!

Posted by Matt Reeves on Feb. 22, 2012 @ 12:58 am