The Biogas Bible
I get more inquiries about my biogas posts than just about any other topic. People all over the world, from Toronto to Bosnia to Pakistan want to know how to construct and run a small scale biogas operation.
Well, here it is. The Biogas Handbook by David House has everything you could ever possibly want to know about making your own biogas. Moreover, with his folksy style, David House manages to make the topic fun to read!
From the book:
(If) “30 percent of the land is planted to corn, an area with an 8-mile radius will produce enough cornstalks to supply a city of 80,000 inhabitants continuously. In other words, the cornstalks from one acre will produce the gas for one person for a year.”
Note: You can provide the natural gas requirements of a city of 80,000 with the agricultural waste left in the fields nearby!
This book is a must have for local first, alternative energy folks. Using just leaves and grass clippings + kitchen waste, you can provide a significant fraction of your energy requirements.
Get the book:
Good Tire Gauge – Save $500.00+ Per Year!
When tires are not inflated to the recommended PSI (pounds per square inch) as recommended by tire manufacturers, the flat part in contact with the ground is greater and the tires require more energy to flex as they roll. This phenomenon is known as rolling resistance. Rolling resistance goes up as pressure goes down. Low tire pressure reduces the efficiency of your car and shortens the life of your tires – a double penalty.
Tire inflation has become a smoldering issue this election season. Let’s look past the smoke to see if inflating your tires can really save a measurable amount of energy.
From About.com, “Keeping Your Tires Inflated” (with a few edits)
An informal study by students at Carnegie Mellon University found that the majority of cars on U.S. roads are operating on tires inflated to only 80 percent of capacity. (One Dept. of Transportation study has it at 80% of all vehicles have under-inflated tires, 27% have tires under-inflated by 25% or more) According to the website, fueleconomy.gov, inflating tires to their proper pressure can improve mileage by about 3.3 percent, whereas leaving them under-inflated can lower mileage by 0.4 percent for every one PSI drop in pressure of all four tires.
That may not sound like much, but it means that the average person who drives 12,000 miles yearly on under-inflated tires uses about 144 extra gallons of gas, at a cost of $300-$500 $576.00 a year. And each time one of those gallons of gas is burned, 20 pounds of carbon dioxide is added to the atmosphere as the carbons in the gas are released and combine with the oxygen in the air. As such, any vehicle running on soft tires is contributing as much as 1.5 extra tons (2,880 pounds) of greenhouse gases to the environment annually.
Lets Check The Math:
There are about 250 million vehicles on the road in the U.S. Some are trucks, but trucks need to keep their tires inflated too. The average distance driven in a year is 12,000 miles. With 80% needing to inflate their tires – that makes 200 million of us driving on low tires, each adding an extra 1.5 tons of CO2 to the atmosphere.
200 million cars with under inflated tires x 144 gallons of gas per car per year = 28,800,000,000 gallons of gas.
28,800,000,000 gallons of gas divided by 19.6 gallons of gas per barrel of oil (U.S. Energy Information Agency) = 1,469,387,755 barrels of oil per year.
According to estimates from the Interior Dept.’s Minerals Management Service (MMS), the U.S. has roughly 18 billion undiscovered and technically recoverable bbl. of oil offshore. Total. It would take a decade to get the first barrel to flow and we could recover maybe 1 billion barrels per year.
In other words, if we inflate our tires to the proper pressure we would save just about the entire amount of oil available offshore before the first barrel was pumped. Furthermore we save more oil per year than offshore drilling will product. Period. Offshore oil will flow at a rate less than what we can save by inflating our tires, and we have the additional benefit of not emitting 1.5 tons x 200 million cars x 10 years – 3 billion tons of CO2 in the interim.
Looks like inflating our tires is a smarter policy.
Make it easy to check your tires, this Accutire Gauge has big numbers and is easy to read in bright daylight. This gauge is heavy duty, easy to grip and it beeps when it has a correct reading. Pretty foolproof.
Solar Emergency Power
CDT-10w 12V crystalline PV module
I’m working on a solar / LED lighting project for people who live off the grid in Guatemala and Nicaragua.
Listening to people who live way off the grid in very rural parts of Guatemala has given us insight into what people really need for their lighting. Some non profits advocate 1 watt of LED light to replace kerosene lamps. And they have a point, one watt of LED light is a lot better than kerosene or candles. However, our entire solar power system + lights costs less than what people spend in a year on Kerosene and candles, and it provides what people really want – which is a little more than a fancy LED lamp. People want a power supply that can charge a cell phone, and possibly run a small transistor radio for a few hours a day.
(In Guatemala they practically give away cell phones. I purchased mine for $15.00 with $15.00 worth of time already programmed in. The phone was essentially free. You can purchase air time in chunks as small as 5 minutes. The cell phone companies know how to work with the incomes of very poor people)
It turns out our design, a 10 watt solar panel and a couple of 7 amp hour 12 volt batteries can provide enough power to keep a cell phone charged, run a couple of 2 watt lights and have a bit extra power to spare for longer times without sunlight.
A little power is a lot more than no power at all.
Now that we have the system designed for Guatemala, I realize it also can work as an emergency back up power system for our frequent black outs here in the midwest. A 10 watt solar panel, a controller and a 15 amp or so battery ( we can actually charge a much larger battery here because we don’t plan on using the system except in an emergency)
What this gives us is enough power to run a couple of 2 watt LED lights (we could go for 4), and a radio for a few days. Eventually we will drain the battery because our daily use is larger than the design for Guatemala but we can also design our system for a lot more storage capacity to start out. With the pattern of black outs here in Ann Arbor, we can expect once or twice a year to have a few days without power. The rest of the time our system is charging and then keeping the batteries topped off. I will have to run the numbers on this, but I expect we can keep somewhere around 500 – 1,000 amp hours topped off with our little 10 watt solar panel, which would give us enough power to run an energy efficient refrigerator on an inverter for a day or two while we wait for power to return.
A little electricity is a lot more than no electricity at all.
We purchased our solar panels at Amazon, they are cheaper than ordering direct from the manufacturer!
The Amazon link for the panels will be added as soon as Amazon sends us a new password for the account.
Till then, if you want to order a good emergency back up power system, consider the
10 Watt Solar Panel – CDT-10w 12V crystalline PV module, plus the Sunforce 60012 7 Amp Charge Controller.
We will cover how to make your own inexpensive LED lights in a future post.
Cheers,
Solar Electricity
The cost of solar electricity has come down and now many states are offering rebates and other tax incentives for you to install your own solar photovoltaic system.
For those of us who are already attached to the electric utility grid, the most cost effective way to go solar is to have a “grid inter-tied” system. This is a system that sends power to the grid when you make more energy than you are consuming, and draws energy from the grid when you need more power. One nice feature of a grid inter-tied system is that when demand is greatest on the grid, on hot summer afternoons, your home system is making the most electricity.
In some states you can sell your excess energy to your electric utility through a program called ‘net metering”. This way you get a credit for every kilowatt you send back to the grid which can be used to offset your utility bill. It is even possible to make a profit from your solar photovoltaic installation, you should check with your utility or your state energy office to find out about what incentives are available and what your situation is regarding net metering.
If you live in one of the unfortunate states that doesn’t have net metering, write your congress person! Net metering encourages more people to install solar, creates jobs and reduces the use of fossil fuels. The utilities lobby against net metering, and they have deep pockets so it takes lots of dedicated people to lobby, write letters and basically harass your congress people to get them to see the light.
My office has overseen the installation of lots of solar hot water and photovoltaic systems throughout the United States. We have run the numbers and it pays to go solar. The value of a solar system increases with increases in energy costs. Also, solar photovoltaic systems, once installed, have very few problems and require little maintenance.
The largest seller of home solar photovoltaic systems is Gaiam.
Check out Solar: Gaiam Solar Living