Wednesday, April 30, 2014

A DIY Solar Generator for Emergencies

John provides a very detailed description of a small and portable solar generation system that can provide power for emergencies or camping or routine use.

The system consists of a 45 watt PV panel, a charge controller to regulate battery charging, an off the shelf power pack that contains both the battery and inverter, and a PVC pipe rack you make to support the panel.

The system will provide power for things like a laptop, some modest lighting, charging cell phone batteries, and a number of other things that are very handy to have in an emergency.
The instructions are very detailed and the project is easy to build. A good way to get started with solar.

Thanks very much to John for providing this material!

Thursday, April 10, 2014

Four Interesting New Projects from Around the Web

This is a catch up on some new and interesting projects I've seen around the web and and added links to in Build It Solar.
Four very interesting projects...

George Plhak Releases Generation 2 of His Concentrating Parabolic Reflector Solar Array

I was very impressed with George's first generation parabolic solar array, and thought that the plans and documentation were very good.  His new generation 2 document and plan set are even more complete, detailed, and wide ranging.  

George goes over a number of design improvements, lessons learned, and provides much additional reference material for those interested in concentrating solar applications.

This is one of the very few cases where I think you get your moneys worth paying for project plans.

The Lucy Caliente Thermosyphon Solar Water Heater Plans and Construction Manual

This is a very detailed and free set of plans for a simple thermosyphon collector for warm climates (where no freeze protection is needed).

This is a simple system in which the collector is located below the solar hot water storage tank and thermosyphon flow from collector to tank does all the heating -- no pumps or controllers needed.  The hot water gravity feeds to showers or other places it is needed.  Fresh water is added to the tank via a float valve.

I understand that the decoration on the tank increases the performance by 13%.

Making Collector Fins from Recycled Printers Plates

Water heating solar collectors require fins to transfer solar heat into the collector tubes.  Most DIY collector builders use aluminum fins and many ways have been worked out to make them.  

Soren has worked out a way to make solar collector fins from recycled printers plates.  He shows in detail how these free or nearly frees printers plates can be made into effective collector fins.

Thanks to Soren for sending this in!

Biomeiler -- Heat Extraction from Large Compost Piles

There is a lot of interest in extracting heat from large compost piles, but there is not a lot of detailed information online describing how to build a practical pile and extract heat from it.  This project describes in quite a bit of detail the building of a large compost pile with embedded tubes for heating water. 

The large ground wood compost pile in the making.  Embedded tube spirals heat water.
This large compost pile is said to provide temperatures up to 160F and last more than a year.

All the details here....  This is in German, but Google translator and lots of pictures help.

This is another project from the interesting LINARIA E. V. site...

April 10, 2014

Tuesday, April 8, 2014

Build-It-Solar Newsletter

Just started a newsletter for Build-It-Solar.

The plan is to publish the newsletter about once a month.  It will give a brief description of new projects added to the site over the month.  It may also cover some popular or seasonal projects -- and other things that seem note worthy.  Maybe some low tech cooling projects for next months newsletter?

You can sign up using the signup link just to the right.

Let me know if you think there are other things that should be included.

The newsletter is managed by the MailChimp service.  They appear to be responsible about not sharing your data.  You can unsubscribe with a single click at any time.

April 8, 2014

Thursday, April 3, 2014

DIY Shower Water Heat Exchanger

When you think about what goes on energy wise when you take a shower, its mind boggling wasteful. Your hot water tank heats up several gallons of water from about 60F to about 120F typically using about 6000 BTU worth of energy. The water flows over you once, and then right down the drain taking nearly all of that 6000 BTU of energy you just put into it right down the drain.

Tyler has worked out a pretty simple heat exchanger to extract some of the heat from the shower water as it goes down the drain and use this heat provide some of the heat to the incoming shower water.

The grey water heat exchanger is inside the ABS stack on the left.  It joins the
main stack on the right near the floor.

The grey water heat exchanger consists of a bundle of PEX pipes.  The cold water on its way to the shower runs through this bundle of PEX pipes which are inside the gray water drain from the shower.  So, the outgoing hot water draining from the shower transfers some of its heat to the cold water that is on its way to the shower.

The bundle of PEX pipes ready to go into the drain pipe.

The bundle of PEX pipes being stuffed into the grey water drain stack.

Be aware that in many places this single wall heat exchanger design would not meet code.

Tyler gives quite a bit of detail on the construction and performance of the heat exchanger -- all the details here....

Please leave any comments or questions in the comments section at the link above.

Also at the link above is some more information and DIY and commercial grey water heat exchangers.

April 3, 2014

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