Agency approves $7.7 million for solar and other renewable projects at homes and businesses.
Source: State may expand funding for dairy farm digesters
I’m all for alternative energy sources, but putting any kind of tax funding or other subsidies into manure digesters in the belief that they will somehow help deal with the impact of manure on water pollution, well contamination, quality of life problems caused by manure from CAFOs (concentrated animal feeding operations) is utterly ridiculous.
CAFOs like the mega dairy farms here in Wisconsin and other parts of the country, large animal feedlot operations and pork operations that raise thousands upon thousands of animals, produce such large amounts of manure that it is mind boggling. One single dairy farm here in Wisconsin produces as much manure as a city of 180,000 people.
And, of course, that manure has to be disposed of somehow. One of these days I’m going to have to tell you horror of manure disposal here in Wisconsin. I don’t want to get into that now because if I could probably do a thousand words on just that. So let’s stick to digesters.
The idea behind digesters has been around for a long time. The manure is put into air tight holding tanks. Bacteria is added to the mix. The bacteria thrive in this environment, and as they grow and multiply, they produce, among other things, methane gas. Because the tank is sealed, the methane accumulates and is piped off and used to power engines which drive generators to produce electricity.
It sounds rather logical, I suppose. You can produce electricity from cow poo, or pig poo, or whatever kind of poo you shove into the tank. It sounds all ‘green’ and environmental and good for the planet, doesn’t it, producing electricity from manure. It solves a lot of problem, doesn’t it? Gets rid of the manure, makes electricity to keep all of our gadgets running…
Only doesn’t do any of that. Not really. Especially not the getting rid of the manure part.
These things are ridiculously expensive, first of all. We’re talking millions of dollars even for a relatively small one. Without heavy taxpayer subsidies, no farm could afford to put one of these in. Special holding tanks have to be built, first of all, because they have to be completely sealed to keep the gas in. Otherwise all that methane is going to go straight up into the atmosphere, and since methane is a green house gas that is much worse than CO2.
The gas that comes off these things is highly corrosive. That means all of the pipes, tanks, even the engines used to run the generators, are extremely expensive to make because special materials have to be used to prevent them from just corroding away. Special filter systems have to be installed to remove unwanted elements from the gas, dryers to remove moisture… The list goes on and on.
The whole process is neither efficient, nor is it ‘clean’ by any stretch of the imagination.
Oh, and did I mention they explode sometimes? Like this one that happened at a digester here in Wisconsin. If you click the link to the jsonline article, you’ll note that the project has been plagued with problems from the beginning. And this isn’t the only one that’s had major difficulties. Plug ‘manure digester explosion’ into Google and you’ll see what I mean.
But they generate electricity, right? Well, sort of. Not much. Certainly no where near enough electricity to pay for building and maintaining one of these systems. And it isn’t “clean” energy by any stretch of the imagination because it still generates electricity the good old fashioned way, by burning stuff. Burning methane is cleaner than burning coal or oil, but it still produces waste material like CO2 and other gases.
They’re pushing these things by claiming that they somehow help to eliminate the manure disposal problems CAFOs have. So let’s look at that.
They don’t. I’m sorry, they just don’t. They do nearly nothing to eliminate manure disposal problems.
The digestion process does alter the chemical composition of the manure, I’ll grant you that. It will reduce the amount of phosphorus, and that’s important because it is a major problem around here. Phosphorus runoff causes toxic algae blooms in lakes, causing major fish die offs. We have huge dead zones in the Bay of Green Bay on Lake Michigan that seem to get bigger every year, due to phosphorus.
But that’s all these digesters do, remove some of the phosphorus. And only some of it. About half of it still remains. And the other pollutants in the manure remain virtually unscathed.
And then there’s the quantities involved. You put 100,000 gallons of manure into a digester and what you get out the other end when the process is done is, well, 100,000 gallons of manure. It does absolutely nothing to reduce the sheer quantity of manure.
The single biggest problem with manure is the sheer volume of it, and digesters do absolutely nothing about that. All the digesters seem to be is little more than a lame attempt at ‘greenwashing’, trying to cover up the real problem.