In the heat of August – when Boise residents are cranking up their air conditioners and farmers are pumping water onto thirsty crops – the solar resource in southern Idaho is estimated to be as good as in the desert Southwest.
That’s why Idaho Power Co. has been putting together a pilot project to see how it can best harness solar power.
“It looks like a good fit for our needs,” said Mark Stokes, Idaho Power manager of power supply planning.
Idahoans who have watched the debate over wind power in the Legislature and the Idaho Public Utilities Commission may remain skeptical. The company that at first said it was staying out of debates about whether to renew an alternative energy tax credit or stall new wind projects for two years has landed squarely at odds with the green energy companies.
But utility officials say solar power has the potential to fit Idaho Power’s needs far better than wind. Both are intermittent sources – they generate power only when the sun is shining or the wind is blowing. But the sun shines when it’s hot outside, and that’s when people use more power.
Idaho Power met last week with industrial customers, power developers, consumer groups and conservationists to discuss its “integrated resource plan,” which it uses to map its energy needs for 20 years into the future. With all of the wind projects coming on line and the Langley Gulch natural gas plant under construction, the utility doesn’t see a need for new power sources until at least 2015.
And even then it will need power only during its peak use periods, mostly afternoons on hot July and August days. It just happens that those are the same days when solar power offers the most potential.
And even if a thunderstorm reduces the solar output, Idaho Power’s demand drops at the same time as farmers need less irrigation water and air conditioners don’t have to work so hard to cool homes.
“Idaho Power needs the power when the sun is shining,” said Ben Otto, an energy analyst for the Idaho Conservation League.
Solar power, like most renewable energy sources, takes a lot of capital expenditures up front. That’s why the utility wants to study a range of options to determine what makes the most sense for its customers and its stockholders.
“The cost has to come down,” Stokes said. “It’s still a bit higher than other alternatives.”
One alternative is to hire contractors to place solar panels on existing homes and businesses. But that raises questions for Idaho Power: Who would own and maintain the solar equipment? Who would be responsible for ensuring it is operating when the utility needs it? What about liability?
Idaho Power will get some data from the Idaho Office of Energy Resources’ program to install solar panels on schools using federal stimulus money. But the questions about the business model remain.
Placing panels on existing homes would mean dealing with the different slopes of roofs, Stokes said. That affects efficiency.
The utility also may simply place panels in an array in the desert – a solar electrical-generation plant – where it has more control.
Another, larger alternative is a so-called solar tower: This emerging technology uses the sun to heat air in a large greenhouse at the base of a chimney. When the heated air rises in the tower, it drives turbines.
The heat also can be stored in water to keep the plant generating into the evening after the sun has gone down. If Idaho Power built this larger plant, it could produce 100 megawatts of electricity.
Meanwhile, some companies are moving ahead on their own – though none as quickly as the wind producers have.
A Boise firm called Sunergy World is negotiating with the city to build a solar array on 160 city-owned acres south of town that would produce about 10 megawatts the company would like to sell to Idaho Power.
Micron Technology is even getting in the business, teaming up with an Australian solar company to build solar cells with the technology it uses to create microchips.
Idaho Power’s preferred alternative for meeting its needs over the next 20 years is to build a high-power transmission line that will connect it with Columbia River dams and spot market power available to the West.
The ICL’s Otto doesn’t oppose the transmission lines, but he thinks Idaho Power’s analysis underestimates the future costs of natural gas and power on the open market, and overestimates the future costs of solar panels.
“They are predicting an equal amount of solar costs to go up as go down,” Otto said. “I think that’s wrong.”
Stokes acknowledges that solar panel costs continue to drop as efficiency rises, but associated technology costs could rise, he said.
Still, the company is willing to pay more for solar than wind, “because it’s much more valuable to us,” he said.
How quickly Idaho’s alternative energy sector continues to grow could be set in the next few days. Idaho lawmakers are expected to get yet another version of a tax rebate for renewable power projects this week.
An agreement between wind developers, Idaho Power and other public utilities lumps solar projects in with wind, requiring them all to be approved by the PUC by Oct. 31 and built by the end of 2014 to be eligible for the 6 percent rebate.