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Manure Digestion/Energy Generation

14 Aug 2013

Tuesday, I traveled to Michigan State University (MSU) for the start up of MSU’s South Campus Anaerobic Digester (SCAD). Reportedly, this is the largest such digester in the United States that is owned by a university.

Anaerobic digestion converts organic materials (feedstocks) without oxygen into biogas.

Once fully operational, MSU’s digester will use roughly 17,000 tons of organic waste from MSU and elsewhere nearby to produce biogas that will generate over 2.8 million kWh of electricity per year.

Most of the system’s feedstock will be dairy manure from the MSU Dairy Teaching and Research Center, with some food waste from campus dining halls, fruit and vegetable waste from a nearby Meijer Distribution Center, and fats, oil and grease from local restaurants.

Biogas produced will power a 450 kW combined heat and power system. The electricity generated will power buildings on the south side of campus.  Hot water generated will maintain the digester temperature at 100 degrees F and to help heat other nearby buildings.

The solids and liquid remaining after digestion (digestate) will be pumped to a solid-liquid separator; solids will be composted; the liquid will be stored in the larger tank in the photo and will be applied to the land as carbon-rich fertilizer.

While the technology is proven, MSU will test this digester to see how this can be implemented in a cost-effective manner. The payback at this point is projected to be between 7 and 12 years. There may be many opportunities for these to be located near large farm “hubs” and even as part of municipal wastewater treatment – if they can be operated economically.

Great Lakes Gyres?

30 Jul 2013

Courtesy of 5 Gyres

Three years ago, I blogged about the Atlantic and Pacific garbage gyres where small bits of plastics are found floating in the oceans.

Not surprisingly, plastic bits are also being found in the Great Lakes. This article discusses the issue. Most interesting to me is the assertion that “micro beads” found in toothpastes and various abrading body washes may be a prime culprit.

The 5 Gyres Institute told us that they successfully  demonstrated to some of the largest companies in the world that use polyethylene microbeads in consumer products and a number of them have agreed to discontinue the use of microbeads in their products.

CO law prevents Graywater System at LEED Platinum Dorm from being turned on.

28 Feb 2012

Williams Village North LEED Platinum dormitory.

Stephen Del Percio at the Green Real Estate Law Journal (a great blog by the way) posted an interesting story about the University of Colorado’s new $46.6 million, 131,000-square-foot dormitory in Boulder.  The dormitory is the largest (500 residents) of its size in the nation to earn LEED Platinum from the USGBC.  Here’s the problem, its $230,000 graywater system – which recycles water from showers and sinks through the dorm’s toilets, and could save the dorm over one million gallons of water annually – can’t be turned on by the University because of Colorado state law, which generally prohibits graywater systems from being used unless they’re isolated from public areas.

Apparently, a state bill that would have given municipalities greater control over regulating graywater systems stalled in committee; nonetheless, the University may still be able to operate the system through an exemption that allows graywater pilot programs (although supposedly it could still take more than a year to qualify the system through the pilot program).

This is a great example of new technology conflicting with pre-existing (and frequently outdated) law.  As Stephen aptly points out, when signing contracts which require that work and services comply with all applicable laws, codes, and regulations (which they almost all do), you need to take those obligations seriously – particularly on projects which include newer technology and/or green building components.