Five months ago, one of the country’s ten largest electric utilities told regulators in Minnesota that it needed three new natural gas power plants to handle peak energy demand. This week, the same company’s Colorado division announced plans to use more solar power because it is cost competitive with gas. Maybe they need a memo… Continue reading
Viewing the rooftop tag archive
With the cost of solar continuing to fall rapidly (50% in the past five years) and electricity prices rising steadily, if slowly, the approach of solar grid parity is near. The following chart illustrates the trajectory of solar cost and electricity price, hinting at the coming intersection. 1 The chart compares the cost of a… Continue reading
Solar cells are unusual in that they were cost-competitive from the get-go. From the Apollo space program to highway signs to lighting for buoys, solar could replace highly expensive power from batteries or other sources and eliminate the need for the construction of electric distribution lines.1 When the Institute for Local Self-Reliance was founded in… Continue reading
Solar company Renvu created a delightful whiteboard animation of the results from our Rooftop Revolution research, which automatically makes them cooler than the average solar company. Check it out below or on Youtube. Continue reading
A presentation summarizing ILSR’s reports on the local solar opportunity as unsubsidized solar becomes competitive with retail electricity prices in nearly every state over the next decade. Read the reports and view our other multimedia resources on solar parity. Is Your Utility Ready for a Solar Rooftop Revolution? from John Farrell Continue reading
Last week the Minnesota Public Utility Commission had a rare live public comment period on Xcel Energy’s long term planning process (called an Integrated Resource Plan). At the urging of several fellow clean energy advocates, I gave my 3 minute testimony about the enormous gulf between Xcel’s 10-year plan for solar power and the solar… Continue reading
The City University of New York (CUNY) released a solar map of New York City last week, allowing building owners in the city to determine the amount of solar power their roof could host. The cumulative impact is enormous, with city rooftops capable of providing half the city’s peak power, and 14% of its annual electricity consumption.
The city should immediately maximize solar power development and start saving millions in electricity costs.
At $3.50 per Watt installed, and with the federal 30% investment tax credit (ITC), solar power in New York City can provide electricity at 16 cents per kilowatt-hour (kWh), a full 4 cents lower than the average residential electricity price (as reported by the National Renewable Energy Laboratory’s PV Watts program).
Commercial installations that can also use the federal depreciation tax deduction could deliver electricity for nearly 12 cents per kWh, 40% lower than the average residential rate.
These prices are well within reach. Already in the U.S., aggregate purchasing has driven down residential solar PV prices as low as $4.22 per Watt. The average cost of rooftop solar PV installations in Germany is between $3.40 and $3.70 per Watt. In our new report, Democratizing the Electricity System, we show that even small-scale solar is being built for under $4 per Watt in the U.S.
As it turns out, when it comes to solar self-reliance, New York City is a microcosm of the state (in solar potential if not comparative electricity price). In our 2009 analysis, Energy Self-Reliant States, we found that New York’s statewide rooftop solar PV potential was 15% of its electricity consumption, almost identical to CUNY’s estimate of 14% of the city’s electricity use.
Whether immediately (NYC) or in the near future (NY state), it’s clear that rooftop solar PV is the route to greater energy self-reliance and electricity cost savings.
Update 7/7/11: Wow, ConEdison already has 8.5 MW of solar PV on its system, only 1,791.5 MW to go!
It’s rarely mentioned that a home with a solar array still gets most of its electricity from the grid. In fact, without storage, a typical home solar array might only serve one-third of a home’s electricity use, even if the system is big enough to meet the home’s peak needs. The problem is a mis-match… Continue reading
A new rooftop solar collector can provide thermal energy rather than producing hot water or electricity for space heating and cooling. With inexpensive fresnel reflectors to concentrate sunlight, the Chromasun could prove an interesting way to use distributed solar thermal energy for more than just hot water.
The unit produces temperatures up to 220 Celsius and promises to use less roofspace than comparable systems using solar PV.
Now, what will it cost?