Solar Power and Grid Stability: Scenarios and solutions

hawaii.gridx299Renewable energy is often intermittent, and that variability presents a variety of challenges to power grids. The nature and magnitude of the challenges depends on the time frame — from fractions of a second to seasonal or even multiyear variations — as well as the nature of the grid itself. The latter is evident in two of my articles from last week looking at how seconds-to-minutes fluctuations in solar power complicate grid controllers’ efforts to maintain alternating current at the 60 hertz frequency and the roughly 110 volt power levels required by North American devices.

Fluctuating AC frequency stars in my Technology Review dispatch from the paradise of Kauai, where the island utility is riding an electrical roller coaster as it pushes solar towards 80 percent of peak power flows Continue reading

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Minnesota Finds Net Metering Undervalues Rooftop Solar

Utilities should be paying more for their customers’ surplus solar power generation according to a solar pricing scheme approved by Minnesota’s Public Utility Commission last month and expected to be finalized in early April. Minnesota’s move marks the first state-level application of the ‘value of solar’ approach, which sets a price by accounting for rooftop solar power’s net benefits, pioneered by the municipal utility in Austin, TX.

Minnesota is one of 43 U.S. states that requires utilities to pay retail rates for surplus solar power that their customers put on the grid. Utilities across the U.S. are fighting such net metering rules, arguing that they fail to compensate the utility for services that their grid provides to the distributed generator. So last year pro-solar activists and politicians in Minnesota called the utilities’ bluff, passing legislation tasking the state’s Department of Commerce with calculating the true value of rooftop solar power. Continue reading

Life’s a ‘Paternoster’ (and then you fly)

Solon SE’s new paternoster lift. Credit Kevin Matthews / ArchitectureWeek.

“Don’t leave the planet to the stupid.” The corporate tag line from German solar module manufacturer Solon SE screams: ‘We reject complacency’ (not to mention gentility). It’s a slap-in-the-face warning to expect the unexpected, so I was looking for something completely different when I visited Solon’s one-year old Berlin headquarters on an architectural tour of Germany last week. I was not to be disappointed. What I found is probably the first cyclic elevator system installed anywhere in decades.

No pressing a button and waiting for a lift with this modern incarnation of a late-19th-C elevator design! In a cyclic elevator a string of passenger cars run by in a continuous loop. One simply steps into one of the open cars scrolling up or down through its adjacent elevator shafts and takes off. To your weary Canadian correspondent, presently immobilized in Berlin by an angry planet, the hassle-free transport offered by Solon’s cyclic lift was a source of almost drunken pleasure.

Unfortunately, it may also be quite stupid (so to speak). Continue reading