Renewable Energy Training: Greenhouse Gas Offsets and Sequestration on Braeside Farms

This is the first in a series of blog posts focusing on renewable energy. This one focuses on our efforts to offset greenhouse gasses on our farm as an example of what can be done.

Much news has been made of greenhouse gas offsets and sequestration in recent months. The discussions have largely focused on ways large and small entities (countries, states, counties, cities and towns) can reduce their carbon footprint. From vegetable oil based diesel fuel replacement to biogas digesters, the concepts of offsetting and sequestration center around the notion that when one group produces a greenhouse gas, for example CO2, that group could offset their emissions in a number of ways. Methods include: installing more efficient systems like radiant underfloor heating; composting wastes; capturing greenhouse gasses; using an ethanol still; or, in the case of trading, buying “credits to pollute” from a less polluting group.

On our farm, we are doing our part to create offsets and sequester green house gasses. Due to our small size, trading is not really an option. So how do we offset our greenhouse gasses and what are we doing to become greenhouse gas neutral? Check it out!

Fuel and Lubricants Consumption

Fuel and equipment lubrication are a part of our daily work. Machines make the work easier and the output greater. Oil-based fuels are a major part of our greenhouse gas emissions. We reduce our impact by doing the following:

We annually use 1200 gallons of diesel fuel.

• We offset 500 gallons of this by replacing it with 500 gallons of farm made biodiesel.
• We are working to reduce our total consumption to 550 gallons by 2020.
• This will leave us using only 50 gallons per year of petrol diesel fuel.

We use 50 gallons of gasoline annually.

• We offset 5 gallons of this by replacing 5 gallons with farm grown and made ethanol.  In fact we think fuel alcohol is so cool, we are now adding a drinking alcohol distillery to our farm!
• We are working to increase our production and consumption of farm made ethanol to 43 gallons per year. This is difficult because of the lack of ethanol friendly engines available in the US.
• This will reduce our use of gasoline to 7 gallons per year as we phase in the more tolerant engines.

We use 25 gallons of lubricants per year (i.e., engine oil, gear oil, hydraulic oil and bar oil).

• We recycle this used oil which is re-manufactured into new oil.
• We replace 2 gallons per year of petroleum bar with waste vegetable oil.
• We are experimenting with recycled and vegetable based engine, gear and hydraulic oils to eliminate our remaining 23 gallons of oil.

We use 20 gallons of propane per year.

• We are replacing all of this with an aerobic digester that is fed with farm generated manure and harvest wastes. It is a carbon negative system.  This is one of the fuel sources we plan to use to power our new drinking spirits distillery.

Soil Building

On our 2 acres of vegetables we sequester between .7 and 1 tons of CO2 each acre each year.

• We do not till the soil. Instead we lightly turn over the top 2-4 inches of soil after we have added compost. This greatly slows the release of carbon and maintains soil life. For a wonderful and compelling example of the benefits of not tilling watch the movie Rebecca’s Wild Farm by Rebecca Hosking.
• We grow in wide planting beds using 75% less space than a “conventional” farm to grow food. This means more soil depth and less soil breadth. Think of the carbon stored in the ground like population density in a high rise apartment building vs. in a suburban development.
• Our unplanted areas are kept in cover crops. These areas capture runoff nutrients, which are returned to the beds after the crops are harvested.
• We leave crop residue in place after harvest so the carbon and nutrients in the stalks, stems, roots and leaves are turned back into the soil.

Building Heating

We have 9 acres of “agroforest” on the farm. In this area, crops, livestock and trees are grown side by side. Trees are damaged or blown down every year on the farm by winds and rain. We carefully harvest 5 cords of fire wood (a cord is the size of a pickup truck bed) per year to heat our buildings. The agroforest regenerates about 6 cords per year in regrowth.

• Each acre of agroforest in our ecosystem sequesters .7 tons of CO2 per year. We continuously recycle this CO2 by burning firewood and harvesting the same amount or less back out of the forest each year.
• The result of our wood based heating is carbon neutral or carbon negative.

Electricity

We use electricity for power, backup heating, water pumping, crop refrigeration, etc. We don’t have access to natural gas and only use propane for small heating needs.

• The farm uses 30,000 kilowatts per year. By comparison the average home uses 28,000 kilowatts per year if it is heated by an electric furnace and half of that if heated by gas or other sources.
• We get our power from Portland General Electric’s Renewable Energy program. Hence our power use is offset with renewable power to make our consumption carbon neutral.
• By installing compact florescent lighting, turning down the backup heating thermostats and carefully monitoring our freeze protection equipment, we have reduced our overall use by 10,000 kilowatts per year.
• We are building a wood boiler to reduce our electric heating needs further. We estimate saving another 2,000 kilowatts per year.
• We use refrigeration to keep harvested crops at the proper temperature for freshness. We are building a ground supplied cooler to reduce the need for refrigeration. This is expected to reduce our electricity use by another 4,000 kilowatts per year.
• We are testing an aerobic digester designed to heat the soil under seedlings. This device will eliminate the need for electric heat mats to start crops in the spring.
• We will reduce our total electricity consumption to 10,000 kilowatts per year by 2020 using the above methods. At this level of consumption, we could easily generate our own power using a medium-sized, home scale solar panel array.

Forestry

We have set aside 7 acres of wildlife area on the 21 acre farm. This 60-year-old forest stores 1 to 2 tons of CO2 per acre per year. Depending on which forestry study is used to determine sustainability, we can begin to harvest 1 cord of firewood or the equivalent in lumber out of the forest every year starting this year. That level of extraction is also carbon neutral as long as no more is taken annually. Without some harvesting, we increase the likelihood of a forest fire which would add greenhouse gasses to the atmosphere.

Animal Feed

Grains: Our animals eat grasses and grains as well as vegetables that are unfit for our customers. We purchase approximately 8,000 lbs of grains per year, mostly corn and soybeans. We also use approximately 10,000 lbs of waste brewers grains per year for animal feed.

• We are working with fellow farmers to eliminate Midwest-grown corn and soybeans from our feed rations and replace them with Oregon-grown barley and peas.
• We are increasing the amount of vegetables and pasture foods in our livestock’s diet. We anticipate we will be able replace all but 4,000 lbs of our grain usage per year with on-farm grown feeds.
• We are, as mentioned above, building a drinking spirits distillery on our farm.  The spent grains, sunroots, apples, grapes, etc., from the distillery will be fed to our livestock.  These distillery co-products also reduce the amount of off-farm feed for the livestock and hence reduce our need for fuel to pick up purchased feed.

Hay: We purchase 14 tons of hay per year to feed our livestock.

• We have reduced this amount by 4 tons by improving their pasture.
• We expect by 2011 we will need to buy only 6 tons of hay for our livestock by continuing to improve and expand the quality of their pasture.
• By 2015 we will have improved the diversity of the pasture crops and the access they have to their grazing area; we will need only 2 tons of hay per year. We expect to harvest this from our own land.