[Photo from Connors934 on Flickr]
A few weeks ago I was at Mass Maritime Academy and was impressed by their efforts to use and prove out solar powered lighting for their walkways.
The lights illuminate the northwest campus areas around the dormitories and dining hall. The lights, provided by SolarOne® and Hadco, are powered by photovoltaic (PV) panels, making them completely independent of the electric grid. With their own solar power source, the light posts can easily be installed wherever light is needed, without expensive investments in trenching, cabling and repaving. “We now have a beautifully lit walkway students are using extensively, day and night” said Capt. Allen Hansen, who championed the alternative energy project and is Vice President of Operations at the school. The new lights replace an old assortment of low pressure sodium fixtures and overbearing flood lights, the combination of which left the campus spotty, dark and poorly lit. Instead of adding safety, the old lighting created isolated pools of glare between dark areas. With no underground power conduits, the easily installed PV-powered lights were readily and economically placed along walkways and around the dormitories, which previously had no site lighting….The softer, whiter directional LED lamps provide exceptional clarity and visibility on areas that require light, without sending stray light into areas that are best left dark. The result is an enhanced night time setting, with marked reduction in light pollution and energy usage.
In the United States, we generate most of our electricity by burning coal to heat water and use the resulting steam to turn a turbine which generates electricity. There are other sources of fuel in our energy portfolio, but most of it still comes from coal, the most carbon-rich fuel on the palette. We get some of our energy from other fossil fuels like natural gas and oil as well, and it’s likely that we will not be able to continue withdrawing from our energy bank forever. Some people believe that we have or about to reach a peak in oil production, meaning that we have taken the easy stuff out of the ground and are faced with the unpleasant and difficult task of chasing the last drop. Whatever your reasons for wanting to see us reduce our dependence on non-renewable foreign sources of energy, it makes a lot of sense for us makers to look at solar energy. Fortunately, the sun still shines on the ground, where its energy can be harvested, used and stored.
[Photo from Connors934 on Flickr]
The Vineyard Energy Project aims to reduce Martha’s Vineyard’s dependence on off-island power:
Solar Energy is a great way to get us started on the road to becoming a Renewable Energy Island and help us achieve greater energy independence. Generating power and making hot water on island homes and businesses reduces our contribution to Climate Change, particularly when combined with energy efficiency efforts. Energy generated locally is more efficient because there is less transmission loss.
Editor’s Note: This post is part of a series of posts sponsored by GE. GE had nothing to do with the content of the article and no control over Make: Online editorial. -Gareth
Passive solar
[Image from EcoHomeDuluth]
One relatively low-tech way of harnessing the power of the sun is by designing for passive solar gain. The Arizona Solar Center has a wealth of info on passive solar. By using passive solar design, you can take advantage of the sun and the earth’s abilities to generate heat in the winter months and to cool you off during the summer months. By using the standards of passive solar, your house will need fewer energy inputs to keep it cool in the summer and warm in the winter.
Solar Hot Water
[Image from Freedom Energy Systems]
With Solar Hot Water, or SHW, you are using the solar energy as heat. With that heat, you use water as a carrier for the energy, and then store that in your house. The heated water can be used as domestic hot water, or if your heating system uses fluids, you can heat your living spaces with the hot water from the panels.
Photovoltaic
SHW is different from PhotoVoltaic in what the systems do with the energy from the sun. PV converts the sunlight to electricity, which can then be used to run your arduino controlled projects, or fuel your electric vehicle. The idea of putting up a PV system on your vacation getaway is very attractive to some, as it give a chance to mess with the systems, and may be more cost effective than running power lines to a distant campsite. PV solar can also be a clean way to provide portable power systems. For a good overview of solar energy and how it works, you might want to check out this video.
Of course, solar energy can be used to harness sheer stupidity to generate kill amounts of heat. A few years ago, my students and I had a lot of fun checking out the solar death ray project, inspired by the cockeyed‘s version. This was before the infamous Mythbusters segment. Unfortunately, we didn’t really document the project very well, so it is only represented by a few low res photos, and some fond memories of Martin’s super human math skills and a bit of spotty vision. I actually had to write into my sub plans: “Students should not take the solar death ray outside.”
[Image from Evergreen Solar]
In photovoltaic solar systems, the sun hits the solar panels, resulting in electricity flow which goes either to battery storage or to an inverter. After the inverter, it goes to the circuit breaker panel, then to the house’s electrical system. Any excess electricity is then fed into the grid. In a smart grid metering scenario, you’d get paid a higher rate for the electricity you generate in the daytime, because there’s more demand for electricity in the heat of the day, when people are running air conditioners and other energy hogging devices.
Recently, some people in my town banded together to raise money to buy a solar array. The bank of panels will be ground-mounted at one of the schools in town. As part of the process of creating the educational component, several teachers were lucky enough to spend the day with Clayton Handleman of Heliotronics. We got a good background in some of the theory and practice of solar systems in this workshop. We also got to try out some of the classroom projects designed around the data gathering hardware, software and network based interface. Participants were totally hooked by the depth of information and curious enough about using the data from the solar arrays currently in use to stay long after the workshop ended in a quest for new understandings of using solar to learn about the world around us. We were able to look at the data from Acton, Mass’ solar array, and some others are available as well. Their Virtual Array Tours are definitely worth looking into. If you’re interested in helping to develop curriculum around teaching solar energy, they would be interested in helping and seeing what you come up with
Schools around the country are discovering that solar energy can power the human mind. Solar Learning Labsâ„¢ catalyze the educational experience by channeling the vision of clean energy into an innovative learning endeavor. This is a highly effective approach for schools, nature centers, green businesses, and other community venues.
Solarfest is an annual workshop festival in Vermont. I have gone a few times with friends and family, and would definitely do it again. It is a kid friendly time with a variety of interesting things to see and do for energy geeks of all ages. The electricity for the event is offset by banks of solar panels that harvest the sun for a while before and after the event. There are lots of vendors there and people who know or want to know about solar and other alternative energies.
Solar simulator in Scratch
Learn more about this project
You may also want to check out this little solar panel simulation made in Scratch. I wrote it a year ago as a way of testing out making variables in Scratch and demonstrating some of the concepts of solar energy. It gives a basic idea of what happens when the sun shines on solar panels, and was originally made for use with a Scratch Sensor Board, but also works on a web browser. If you think that the demo could be improved, feel free to download the file and add your interpretation to it.
If you’re truly goal oriented, you might shoot for a zero energy footprint. Housing systems like the one pictured above combine many of the concepts covered here, passive solar, hot water, photovoltaics, and energy efficiency to create a house and lifestyle that uses very little energy which is offset by what the planet gives off.
Getting out of the dark
Saul Griffith’s piece in MAKE, Volume 18 lays out a compelling argument for why we need to start acting now to create a reduced-carbon future. If we can reduce our dependence on fossil fuels, we can be less dependent on imported energy from unstable regions of the world. By generating more of our energy needs sustainably, our society can become better stewards of the environment. Making our systems as efficient as possible will reduce our appetite for energy further still.
There are some great teaching resources for classroom use.
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