Photovoltaic Systems

Archive for the ‘Alternative energy’ Category

On average, about 18% of home energy consumption is for water heating, the second largest consumer behind space heating.  The primary technology used to do this is the tank-type water heater (both gas- and electric-powered), but solar water heating can be a cost-effective way to generate hot water. 

Solar hot water systems vary, and one system we’ve mentioned previously is a passive-pump system by Virginia-based Sunnovations.  This video explains it.

Sunnovations offers a system with less parts, less maintenance, and a one-day installation because it doesn’t have a pump, controller, wiring, or expansion tank.

Sunnovations uses a geyser pump, or bubble pump, that starts working as soon as fluid in the system warms.  The gravity-fed system naturally circulates water, so, as explained in the video, a homeowner may get warm water even if the power goes out.

[+] Learn more about solar hot water from Sunnovations.

Related Articles on JetsonGreen.com:

1. Low-Cost Solar Thermal by Sunnovations
2. Building Integrated Solar Hot Water by GLE
3. Cogenra Mixes Solar PV and Hot Water

One Block Off the Grid took a stab at answering the question: “How big a backyard do you need to live off of the land?“  It turns out, plants like corn, wheat, fruits, grains, and vegetables take a lot of space.  Also, to offset the electricity required to power the average home in the U.S., which consumes about 11,040 kWh per year, one needs about 375 square feet of solar PV, or 25 average efficiency solar panels getting seven hours of sun.  Check out the full infographic:

[+] View the entire infographic at 1BOG.

Credit: 1BOG. 

Related Articles on JetsonGreen.com:

1. How Water is Wasted at Home [Graphic]
2. Solar Increases Home Property Values
3. Huge Solar Rack Structure Installed in NJ

This is the donQi urban wind turbine, which is assembled in Rotterdam.  It’s an interesting small wind product and the subject of a recent article in the September 2011 issue of Dwell.  In the article, Second to None, Jane Szita describes a Passive House near Amsterdam by architect Pieter Weijnen.  The home has some beautiful Japanese-style charred siding and a sleek-white, residential donQi.

The donQi was originally installed directly on the home, but Weijnen had to move it because the vibrations ended up being too noisy.

Which raises an issue that comes up with residential-scale turbines.  People look at new turbine styles, such as the Honeywell Wind Turbine, and think about planting the turbine on the roof.  That may or may not be a smart idea — i.e., hire a great engineer — because vibration and noise will be an issue.  Make it easy, install it separately.

[+] More info on Rotterdam-made donQi urban wind turbines.

Credits: donQi. 

Related Articles on JetsonGreen.com:

1. Eddy GT Home VAWT Installed in Florida
2. Building Integrated Wind in Chicago
3. Eddy: Sleek New Small Wind Turbine

Michigan-based Great Lakes Electric has a solar hot water product with evacuated tubes that allows for creative building-integrated solar hot water.  By releasing the restriction of roof mounting, as with typical solar hot water products, GLE’s unit allows for more innovative placement and ends the worries of roof penetrations and units looking like large black rooftop tarps.

These evacuated tubes are made of two concentric tubes, the center filled with water in the collector pipe and a second to form the vacuum.  The vacuum gap between the collector pipe and exterior allows for a reduction in heat loss over flat pane collectors.

Evacuated tubes generally outperform traditional solar hot water designs in cloudy or cold conditions while flat pane systems typically have the efficiency edge in direct sunlight conditions.  (Similar to the comparison between the thin film amorphous silicon (peel and stick) solar vs traditional PV panels).

When designing the system it should be placed in a location with East – West exposure to allow for full day solar collection.  With larger diameter evacuated tubes compared to most other evacuated tube manufacturers, the system requires less installation area by allowing it to mount vertically.

GLE’s introductory unit retails for $2,500 and produces approximately 56,600 BTUs per day.  With four different standard sizes GLE can select the proper unit for your hot water load.  The system is recommended for any hot water need, such as pool heating, domestic water heating and radiant floor heating.

[+] More info about GLE solar hot water systems.

Photo Credits: GLE Solar. 

Related Articles on JetsonGreen.com:

1. Cogenra Mixes Solar PV and Hot Water
2. 60 Homes Get Velux Solar Water Heating
3. Roof Integrated Solar with Ceramic Tiles