Do not underestimate the Power of the Cow in terms of saving the environment and providing us with energy.
Cows (and a few other animals) can provide us with power and energy through their manure (the average dairy cow creates about 100 pounds of manure a day). Manure naturally releases methane gas into the atmosphere.
Companies, such as Utility Company PG&E (PCG), can take this manure and flush it into a tank or a tented lagoon, where the manure can decompose and the methane gas bubbles off, before being captured under the cover. The gas is then pumped from the digester, then purified and compressed into gas pipelines. After purification, the methane gas is the same as traditional natural gas, except that it's renewable and cleaner.
Cow Power Can Save the Environment Too
If we allowed the methane gas just to reach our atmosphere, this would be harmful to the environment. It is said that methane gas is 20 times more damaging to the environment than carbon dioxide.
A lot of the information above comes from PG&E (PCG), the Utility Company. It has a forward PE of 12.73, a yield of around 3.60%, and a five year estimated growth rate of 7.73%. Incorporating the dividend yield in the PEG ratio, PG&E has a PE to Growth Ratio of around 1.12, which is a reasonable value.
They also provide a website:
and click on the Cow Power link.