Green Options » greenhouse

Carbon Offsets: Creating Something Real from Hot Air

Paul Smith — Thu, 07 Feb 2008 20:42:44 +0000

You’ve probably heard about carbon offsets. They’re everywhere these days, and it seems not a week goes that I don’t hear about a company pledging to go carbon neutral. And yet, it all seems so…full of hot air. What’s real? What do they really do? Which will make the most impact? How are the different purveyors, well, different?

I have a suggestion: Take a look at LiveNeutral.

Why? Well on a basic, financial level, they are a non-profit. And? And that means that offsets purchased through them are tax deductible. More, you say? The resulting lower overhead means better priced offsets as compared to similar for-profit companies offering similar quality offsets.

Mary, Mary, Quite Contrary, How Does Your Garden Grow? Vertically?

Max Lindberg — Tue, 29 Jan 2008 06:34:20 +0000

Lettuce and biodiesel too, that’s the plan of Glen Kertz, CEO of Valcent Products of El Paso, TX. Kertz, who has worked in the greenhouse business for nearly two decades, believes the time has come to localize and simplify food production, and he says his Vertigro system will do just that. I spoke with Glen while he was attending an Orchid growers convention in Miami FL. We talked about his High Density Vertigal Growth System for both vegetables, and algae.

“The HDVG system grows plants in closely spaced pockets on clear, vertical panels that are moving on an overhead conveyor system. The system is designed to provide maximum sunlight and precisely correct nutrients to each plant. Ultraviolet light and filter systems exclude the need for herbicides and pesticides. Sophisticated control systems gain optimum growth performance through the correct misting of nutrients, the accurate balancing of PH and the delivery of the correct amount of heat, light and water“.

If you haven’t seen one of the many news stories on TV about Glenn’s system, you can visit the Valcent site and watch a video with Glenn on the High Density Vertical Growth System.

Getting Local Food

Philip Proefrock — Wed, 14 Feb 2007 14:12:09 +0000

Photo credit: Brines.org
There is a huge variety of food available throughout the year in grocery stores in the US. In most places, this is due to several factors: far distant farms situated in temperate climate regions; varieties of plants that have been bred to produce food that will ripen slowly and be hardy enough to withstand the rigors of packaging and shipping; and a transportation infrastructure that brings them to our stores. Unless you live in a southern state, much of the produce in your local stores right now is being shipped from far away.

All that shipping has an associated cost (financial cost as well as energy use and carbon release). Locally grown food has many adherents. There are hundreds of farms operating as community supported agriculture (CSA), where people buy memberships in the farm and receive a share of produce (usually on a weekly basis). CSA farms are wonderful for getting food locally, but they are usually tied to the local growing season, meaning that they don't have produce during the winter. But other options can allow even more extension of the growing season.

Even in cold-weather climates, for example, it is possible to grow some vegetables year round. In my area, a local farmer operates a zero-energy greenhouse with which he grows a range of cold-tolerant greens ("various lettuce, spinach, arugula, claytonia, mache, carrots, leeks, cress, tatsoi, pac choi, mizuna, and kale to name a few") throughout the winter. These are sold at the local farmers' market on weekends. (Interestingly, on cold winter days at the market, he often keeps the greens in an insulated cooler - not to keep them cool, but rather to keep them warm and prevent them from freezing.) The Brines Farm hoop house uses a frame covered with greenhouse film to create an enclosure to admit sunlight and retain heat in order to maintain a suitable growing environment. The project is well documented, and they have also produced a pamphlet with instructions for individuals who are interested in setting up similar enclosures for themselves. The pamphlet says a 12' x 12' greenhouse can be built for $200 or so.

A more unusual possibility has researchers have looked at the possibilities for a compost heated greenhouse. Composting gives off heat as the organic material is broken down. However, composting also releases carbon dioxide into the atmosphere. While plants require carbon dioxide for growth, in one test case, the CO2 created from composting was 6 times as much as the plants in the greenhouse required, and other by-products were also many times more than what was needed for a balanced system.

Supporting and choosing locally produced food reduces the carbon footprint for the food we do eat. For the DIY-inclined, building a hoop house is an easy project that makes it possible to have an extended growing season and be able to have locally produced food of their own.

Links:
LocalHarvest list of CSAs
Brines Farm
Hoop House instructions (PDF)
Compost Heated Greenhouse