Frugal Living Energy Ideas

Here are a few solar energy and energy conservation projects selected from the Project areas of Build-It-Solar that:

  1. Are quite inexpensive to build

  2. Have very short payoff periods

If you think "one year payback solar" is an oxymoron, have a look below.



If you have any other ideas, please let me know, Gary.


More cheap ways to save energy:

Report Broken Links ...

Simple Energy Saving Ideas
Many more ideas in the Conservation section
Some ZERO COST Energy Saving Ideas

Details Here ...



These are some ideas that don't cost anything at all, and will definitely save energy, money, and greenhouse gas.

If you have any more, please let me know.


Bubble Wrap Window Insulation


New Installation Instruction Sheet (8/15/06)

AND, The Card Board Shutter
Based on the popularity of this Bubble Wrap window treatment, here is a Cardboard Shutter

A really cheap and quick way to insulate windows that you don't need a clear view out of.

Added some small updates to instructions 11/13/05.
Instruction sheet added 8/15/06

Added the Card Board Shutter -->

Urban Options  -- ...


A very good guides for decreasing air infiltration and improving insulation.  Well written and detailed.

Plus a nice energy saving check list for the most important items.

Energy Saving Success Stories A selection of stories (with specifics) from people who saved a lot of energy, and projects they used to accomplish this -- many are inexpensive and have rapid paybacks.
Frugal Fridge
Very Efficient Chest Refrigerator

Chest Fridge Full Article (68K pdf)

This article is from the Mt Best -- Australia solar house site:  A very interesting solar house with several unique features, and a bit more info on the chest fridge.

This refrigerator, which is a converted chest type freezer uses only about 0.1 KWH per day.  See the article for details.

Comment: This chest freezer converted to conventional fridge is amazing.  If you can pick up the freezer cheap (used), the conversion is not expensive.  The saving per year might be (700KWHR - 40KWHR)($0.1 per KWHR) = $70 per year in electricity.

Solar Batch Water Heaters --

Plans for two very simple batch water heaters are listed below -- payoff periods could be well under a year if you can scrounge some of the materials.  More plans for in the water heating section.

The Integral Passive Solar Water Heater Book, David Bainbridge

Download this book

This book is out of print, and difficult to get, but David Bainbridge has agreed to make it a free download.



This is a really fine book on all aspects of designing and building a wide variety of solar batch water heaters.

The book has a great mix of how-to and engineering design information -- great for builders and experimenters.

Thanks to David, the full content of the book is available here as a free download.

Maine Solar Primer Batch Water Heater

Maine Solar Primer

A simple solar batch water heater design suitable for summer use in a cold climate, or year round use in a warm climate.

Courtesy of the Maine Solar Energy Association.

Comment: If the pipes running to and from this collector are protected from freezing, this design could be used through the entire winter.  You just have to be careful to make sure the lid gets shut on cold nights.  A reflective material on the inside of the lid would help winter performance greatly.  The cost for this project could be very low depending on the state of your scrap pile.  Used water tanks are typically free -- just be sure to test it before use.  This might save a family of 3, using 15 gals each per day, and heating with electricity at 10 cents per kilowatt hour. 

(45 gal/day)(8.2lb/gal)(365days/yr)(120F-50F)(0.7)(1 BTU/lb-F)(1 KWH/3412 BTU)($0.1/KWH) = $190 per year.

For natural gas water heaters the saving (assuming gas at $1 per therm) would be about half as much.

Nick Pine and I are working on a much improved version of the experimental "DHW Pond" water heater shown on this page that will be efficient and very cheap.

Solar Energy Association of Oregon

(Note: this link is temporarily unavailable while they reorganize their site -- try searching their site for something like "batch heater")

Detailed plans and performance data for a simple batch solar water heater.

Comment: Another simple batch heater -- spring, summer, fall use only.

Compost Powered Water Heating
Composting Greenhouse with Straw Bale Foundation, From Experiments in Sustainable Urban Living ...

 This uses surplus heat from a large compost pile under the greenhouse floor to heat water for the house.  You get water heating and greenhouse space with the same structure!

I hesitate a bit to put this project in here, as it seems a bit experimental, but it looks like its a potentially good idea that provides both water heating and greenhouse space for cheap.

This is a pretty slick idea for heating water with heat generated from compost, as well as providing greenhouse space.
The thing that intrigues me is that you can apparently have working greenhouse space above the heat generating compost pile? 

More on heat from compost here ...

I'd like to hear from anyone with composting experience on how workable this all seems? Gary
Space Heating

There are some other inexpensive solar air collectors on the space heating and Sunspace pages.

These simple, cheap systems will save as much energy and greenhouse gas emission as a $20,000 solar PV system!

Solar Barn/Workshop


A simple and inexpensive thermosyphon solar space heater for a garage, barn, or workshop (or maybe for a more finished space with some changes).

Comment: This is my barn heater.  The same concept could also be used to heat a home or cabin.  The total cost of this 160 sqft solar heater was $350 with all new materials.  On a sunny day it produces heat equivalent to burning 2 gallons of propane in a furnace.   The payback could be inside of a year in some climates.

Low-Cost Versatile Hoop Houses for Home Heating

George DeVault

Mother Earth News


More information on this concept from the William Shurcliff book:

If you liked this Shurcliff idea, then have a look at lots more of his ideas here -- this is my all time favorite solar book: Shurcliff "100 Daring Schemes"


Mother Earth News Article, Issue 196

Good article on building and using “hoop house” greenhouses, which provide a very low cost per sqft greenhouse.  Some construction detail.  This technique could also be used for inexpensive sunspace for generating solar heat for your house.

Many other construction variations here: Sunspaces

Comment: This type of sunspace can be built very inexpensively, and can provide substantial heat to an attached house, and some plant growing space for some of the year.  The best idea for transferring the maximum amount of heat to an attached house is to 1) build the sunspace large, 2) include very little thermal mass in the sunspace, 3) transfer heat during the day, and close off house to sunspace connection at night, and 4) do something to keep the sunspace floor from absorbing heat (e.g. garden bark covered with black poly).   The sunspace can also be built as a quarter of a cylinder against the house's south wall, rather than the full half cylinder version shown above.

Garage/Workshop Sunspace



This is simple way to turn your garage into a delightful solar heated and lighted workshop or studio.

My all-time favorite solar project!

9/22/06 -- Completely updated  from earlier description.

Very Inexpensive Solar Shop Heater,
Don R. and George Waterman




Mother Earth News article, Issue 48, Nov/Dec 1977 describes a very simple collector for heating a building..
The cost is kept down to almost nothing by using poly film glazing and some scrounged parts. 

If you can scrounge the blower from an old furnace and find some used lumber, this collector probably takes the prize for lowest cost per square foot -- about 10 cents per sqft.  The payback period where I live is well under a month!

Very Simple, Very Cheap Solar Heater


Mother Earth New, Sep/Oct, 1976. 
This is a very simple thermosyphon solar air heater that was built for $25!

If you don't like the look of the black plastic, you could instead hand a dark shade of shade cloth, or just paint the wall and dark shade.  Substituting something like SunTuf polycarbonate glazing would eliminate the chore of replacing the glazing film every year or so.
"Black Roof" Solar Attic Heater
From "Solar Air Heating Systems", Steve Kornher and Andy Zaugg

The Black Roof Collector



This is a very inexpensive system that uses your dark colored roof as a solar collector.  The cost is very low, and it can be installed with a weekends work.  It might supply about 15% of your heating needs.  It is not for all climates. 
This extracted from the book "Solar Air Heating Systems".
Plans for PVC greenhouses


Free plans for greenhouses, cold frames, and sheds framed with PVC pipe.


Instant Sunspaces  -- How cheap can a sunspace be?

Laren Corie
Download the Feb, 2005 issue


Ed's Zero Cost Sunspace ...

ESSN Journal, Feb, 2005

A good article by Laren Corie on how to build and experiment with inexpensive sunspaces.  The example used in the article cost a grand total of $22, and went together in a couple hours!

A free download.


Here is another very low cost (actually zero cost) sunspace done by Ed.   Details ...

This shows how inexpensive and easy it is to turn a porch into a sunspace that is pleasant to spend time in, and can supply some heat to the house.

Passive Cooling Most of the projects listed in the Passive Cooling section are inexpensive, and have short paybacks in climates where Air Conditioning bills are high.
Solar Landscaping
Landscaping for Energy Efficiency

Energy-Saving Landscaping for Your Passive Solar Home, NC Solar Center (pdf)

Information on landscaping for energy efficiency.  "Carefully positioned trees can save up to 25% of household's energy consumption".


Pool Heating
See the Pool Heating section for more
Above Ground Pool Heating


Installation Manuals

"Three gallons of oil refined and burned provides 400,000BTU ... Once.   Three gallons of oil, made into a 4 by 12 foot solar collector, can provide over 10 million BTUs per year ... year after year"

One example of a simple above ground pool heating package.  Comes in a 21 lb UPS-able package!

About $110 for one panel and $170 for two (the picture shows two panels.

Comment: Pool heating is one of the most cost effective solar heating applications.  The collectors are unglazed, inexpensive, but still very efficient.  See the Pool Heating section for more.

A Couple Other Places to look on this site:
Solar (and efficient) Vehicles


If you are a typical family, a large fraction of your energy budget goes into transportation.  The Solar and efficient vehicles section has a lot of ideas on how to transport yourself around for less money.

Small cars (e.g. the Honda Fit) get nearly 40 mpg, and are a lot more comfortable and safe than small cars used to be.  Scooters, electric bikes, bikes, ... can save tons of money and green house gas, and can offer a short payback.

Passive Solar Homes, especially the "small homes" part.