Solar Power Towers Aren’t the Avian Annihilators Once Thought

Solar power towers have had a reputation as alleged avian vaporizers since preliminary reports emerged in 2014 of birds being burned in mid-air as they flew through the intense photonic flux at California’s Ivanpah solar thermal plant. Their reputation was muddied even more during tests early this year at SolarReserve’s Crescent Dunes power tower in Nevada; the solar thermal plant just recently began producing power. California public radio station KCET reported that as many as 150 birds were killed during one six-hour test in January.

It is obviously upsetting to imagine birds ignited in the name of renewable energy. (KCET reporter Chris Clarke, who has tracked the issue since BrightSource Energy began building Ivanpah in the Mojave Desert, described burning birds as “beyond the pale” in a recent article suggesting that power towers may be finished in California.)

But, upsetting as any killing of birds is, avian mortality is a downside common to many modern human creations—including buildings, highways, and powerlines. The best data on bird mortality at Ivanpah, macabre as it might be, shows the death rate to be small and likely of little ecological significance.

Meanwhile, operational adjustments at both Ivanpah and Crescent Dunes are pushing avian impacts even further below levels that could threaten local bird populations. “The data does support a low level of avian mortalities and hopefully, through adaptive management and deterrence, it will go even lower,” says Magdalena Rodriguez, a senior environmental scientist with the California Department of Fish and Wildlife. Continue reading

Arizona Utility Blinks in Bitter Battle Over Rooftop Solar

Arizona’s biggest utility, Arizona Public Service, is withdrawing its bid to jack up monthly fees for rooftop solar users in its territory. The retreat, tendered last week to the Arizona Corporation Commission (ACC), capped an eventful month in the high-stakes battle between utilities and solar advocates that’s raging across Arizona rooftops. The party with the most bruises is not Arizona Public Service (APS), however, but the ACC itself. The elected body referees the state’s power markets, but all five of its commissioners now face accusations of bias that challenge their ability to fairly adjudicate the rooftop solar dispute.

Arizona’s solar dispute is hot, but not unique. Across the United States utilities are fighting to contain or eliminate “net metering” policies Continue reading

Renewable Minigrids Should Be the End Goal for Rural Poor

The percentage of population with grid access declined in many of the 20 least-electrified nations between 2010 & 2012. Image: SE4ALL

Distributed energy solutions, such as rooftop solar, should be the electrification solution for the 1.1 billion people who are not plugged into a national power grid, not just a stopgap measure. That is the message from a new global industry group, Power for All, launched in New York City this week amidst the latest gathering of the United Nations’ universal energy access program.

Power For All brings together businesses and not-for-profit organizations that distribute off-grid solutions, including solar-LED lights and home power systems. Founding members include San Francisco-based d.light; Arusha, Tanzania-based Off Grid Electric; and London-based NGO SolarAid—owner of solar-LED light global market leader SunnyMoney, which sold 650,000 lights last year.

Their message is that bottom-up distributed energy solutions should be thepreferred solution for assuring universal access to electricity because they are faster, cleaner, and cheaper than extending power grids to rugged or sparsely-populated regions.

Figures released this week by the joint UN-World Bank energy access program—Sustainable Energy for All—lend credence to Power for All’s argument. Continue reading

Hawaii Says ‘Aloha’ to a 100% Renewable Power Grid

Credit: Blue Planet Foundation

Credit: Blue Planet Foundation

Hawaii’s legislature voted yesterday to stake the state’s future on renewable energy. According to House Bill 623, the archipelago’s power grids must deliver 100 percent renewable electricity by the end of 2045. If the compromise bill is signed by the governor as expected, Hawaii will become the first U.S. state to set a date for the total decarbonization of its power supply.

Renewable energy has been booming since 2008 when the state set a goal of making renewables 40 percent of its power mix by 2030, and government and utility incentives ignited wind power and solar installations. By the end of 2013, renewable energy had jumped from 7.5 percent to 18 percent of the state’s capacity. HB623 seeks to extend and turbo-boost that trend, calling for 30 percent renewables in 2020 and 70 percent by 2030 en route to the final leap to 100 percent.

That last jump could be difficult, says Peter Crouch, a power grid simulation expert and dean of engineering at the University of Hawaii’s flagship Manoa campus. “Today I don’t know whether we can do it,” he says. Continue reading

Storing Solar Energy: A great idea caught on contested ground

Adding energy storage to sites with rooftop solar power generation offers a range of potential benefits. A battery can help smooth out solar’s inherently variable supply of power to the local grid, and even keep buildings powered during blackouts. Consequently, power-conversion innovators are developing a host of new products designed to reduce the cost and improve the efficiency of integrated solar-storage systems.

Some analysts project a boom in the co-location of solar and energy storage. GTM Research, for example, foresees that co-located PV and storage will grow from $42 million in 2014 to more than $1 billion by 2018. However, the market is moving slower than it might thanks to a little-discussed regulatory roadblock in the United States.

According to Vic Shao, CEO for the Santa Clara, California-based energy storage startup Green Charge Networks, tightly integrating storage with photovoltaics in some key states—including Hawaii and California—runs afoul of the “net metering” rules by which PV owners earn lucrative retail rates for the surplus power they feed to the grid. Adding storage can disqualify solar systems for net metering, in which utilities can pay their owners wholesale power rates that are several times lower than retail. “That is obviously a pretty big problem for anybody considering solar. That could kill a lot of projects,” says Shao. Continue reading

European Grid Operators 1, Solar Eclipse 0

Solar forecast for March 20 via, with previous days' generation

Solar forecast for March 20 from, with prior days’ solar output

Weather forecasts calling for bright sun today across Europe drove up tensions in advance of the partial solar eclipse that blocked the sun’s rays and plunged much of the continent into a brief period of darkness this morning. Grid operators were bracing for record swings in solar power generation because of the celestial phenomenon. Some power distributors in Germany had warned of fluctuations in frequency, notifying customers and suggesting that they shut down sensitive equipment.

In the end, while clear weather made for some excellent eclipse viewing, the electrical story ultimately felt more like Monty Python’s radio coverage of the 1972 eclipse. As if audio coverage of a quintessentially visual event isn’t absurd enough, the Pythons closed their fictitious report in the ultimate anticlimax, as a sudden rainstorm swept in to spoil the solar spectacle. Europe’s interconnected power grid brought about an equally anticlimactic ending today by delivering rock-solid stability throughout the 2.5-hour eclipse. Continue reading

Solar Eclipse Will Test European Power Grids

imgA partial eclipse of the sun headed for Europe next Friday has grid operators in a tizzy. On the morning of March 20 Europe’s skies will darken for the first time since solar power became a meaningful piece of some countries’ power supply, and the impact could be dramatic.

“It’s a very, very big challenge for the transmission system operators in Europe,” says Enrico Maria Carlini, Head of Electric System Engineering for National Dispatching at Rome-based Italian transmission system operator Terna.

The Brussels-based European Network for Transmission System Operators for Electricity (ENTSO-E) judges in an eclipse impact analysis released last month that it poses a, “serious challenge to the regulating capability of the interconnected power system.”

While an eclipse markedly reduced solar generation in western North America last October according to energy tracking firm Opower, Europe’s far greater levels of solar power make for bigger stakes. ENTSO-E projects that the moon’s jaunt across the sun’s path next Friday could slash more than 30 gigawatts (GW) of solar generation in Continental Europe over one hour if clouds are scarce and solar generation is high. That’s the equivalent of turning off 30 big coal or nuclear power stations. Continue reading