Coming Soon: Cheap light rooftop solar you can install yourself.

Christian Hoepfner with roof

CC BY 2.0 Christian Hoepfner with roof/ Lloyd Alter

There's a lot to see at the Fraunhofer Center for Sustainable Energy Systems in a rehabbed old building in Boston. Fraunhofer is a big German research and development non-profit organization, with a couple of branches in the USA. They have been working with solar power for years, and last year held the record for making the world's most efficient solar cell. Now they are looking to reinvent the way solar panels are installed.

Christian Hoepfner, the director of the center, explains that much of the cost of installing photovoltaics is in the frame they are mounted on, and in the connections, the wiring of it all together. This needs about 26 hours of a qualified electrician and a lot of work by the roofer, and presently totals about $ 4.90 per watt installed.

Lloyd Alter/CC BY 2.0

They have redesigned the solar panel, mounting the photovoltaics on a light, flexible substrate, which has an adhesive back that essentially glues it to the roof. Because most building codes specify roof sheathing that is designed to allow for the weight of a second layer of shingles, these panels should be able to be installed without any engineering expenses or approvals because they weigh pretty much the same as shingles.

Lloyd Alter/CC BY 2.0

A simple connector attaches one panel to the next, which then feeds to a packaged inverter.

Then it gets really clever: an electrician can pull off the meter head (homeowners aren't allowed to do this) and stick a special connector in between the base and the meter head. Then the standard universal car-charging plug is stuck right into the inlet. Nobody has to rewire their house or even go inside. Total installation time: about 10 hours, and a cost of about $1.50 per watt. And it's all as easy as falling off a roof.

I have some reservations. I don't think homeowners should be climbing over their roofs without safety harnesses, and hope that they will still recommend professional installations. I am not crazy about the idea of gluing things to shingles; are there going to be moisture and maintenance issues? What about freeze-thaw issues? I would have preferred that it actually was inserted under the tab of a row of shingles at the top so that it actually acts as a giant shingle. And what about velcro instead of glue? And there is more to American housing than low-slope roofs on suburban bungalows, what is the cheap and cheerful solution for them?

Lloyd Alter/CC BY 2.0

But I like the thinking. It's not just a technical problem they are solving, but they are looking at the regulatory issues, code compliance, safety and ease of use. It's a big complex package, trying to make something simple. More at Fraunhofer. More from the Center For Sustainable Energy Systems to follow.

by Lloyd Alter


Solarbox converts old London phone boxes into free solar charging stations


Two geography students in London have come up with a way to give the city's old red phone boxes a new life. An iconic symbol of the English city, the phone boxes have fallen out of use as the majority of people now have cell phones. Many of the boxes have been discarded, but with the students' Solarbox project, many others will now be converted into free solar-powered charging stations for cell phones and other gadgets.

"I lived next to a phone box in my second year at uni and walked past it every day. I thought, 'There are 8,000 of these lying unused in London and we must be able to find a use for them,'" co-founder Harold Craston told BBC News.

The project reinvents the phone boxes by painting them green and installing a 150-watt solar panel on top. Inside, the boxes have mini/micro-USB and iPhone chargers as well as a screen that runs advertisements while people charge their phones. The advertising pays for the booths so that the charging is free to the public.

The first of six charging kiosks were opened last week on Tottenham Court Road and the other five will be opened elsewhere in the city in April 2015. So far the box has seen about 85 customers a day, but each box will be able to handle 100 phone charges per day. The boxes will be open 5:30am - 11:30pm, 365 days a year and users can expect to get a 20 percent boost in their battery life in 10 minutes.

The team won the Mayor of London's Low Carbon Entrepreneur of the Year Award earlier this year and also won the LSE's Emerging Entrepreneur of the Year award for their idea.

by Megan Treacy



IBM Solar Collector Harnesses the Power of 2,000 Suns

ibmsolarA team of IBM researchers is working on a solar concentrating dish that will be able to collect 80% of incoming sunlight and convert it to useful energy. The High Concentration Photovoltaic Thermal system will be able to concentrate the power of 2,000 suns while delivering fresh water and cool air wherever it is built. As an added bonus, IBM states that the system would be just one third the cost third of current comparable technologies. (more…)

Grid Could Run on 99.9% Renewable Energy By 2030

When a British energy minister argued that wind turbines generate a "mere trickle of non-storable energy", some eyebrows were raised. Sure, there are challenges to shifting to clean energy, but with renewables providing an ever larger slice of the energy pie and with a number of studies showing 100% renewable energy is possible with today's technologies, his arguments were at best outdated, and at worst a severe case of misrepresentation and denial. (more…)