Waste to Energy

Biomass cofiring has the potential to cut emissions from coal-fueled generation without substantially increasing costs or infrastructure investments. Research shows that when implemented at relatively low biomass-to-coal ratios, energy consumption, solid waste generation, and emissions are all reduced. However, mixing biomass and coal does create some challenges that must be addressed.

Compared with other solid fuel–fired plants, the systems and components required for handling and processing biomass appear quite familiar, but important fuel differences must be considered. A successful biomass plant design must provide flexibility for handling the expected wide range of biomass fuel properties and characteristics.

Though electricity generation has entered a key period of transition—as investment shifts to low-carbon technologies—world electricity demand is set to grow faster than any other “final form of energy,” the International Energy Agency (IEA) says in its latest annual World Energy Outlook.

The 47-MW Colmac Energy facility is the largest biomass-fueled power plant in California. Colmac operates with a capacity factor consistently in the 92% to 95% range and at a net plant heat rate comparable to waste coal facilities. Colmac Energy has demonstrated that biomass plants using urban wood wastes as fuel can generate significant environmental benefits, including reduced air pollutants from open-air burning and lowered demand for landfill space.

At Malaysia’s first waste-to-energy plant, municipal solid waste (MSW) is converted into refuse-derived fuel for use in an integrated steam power plant. This facility was designed to achieve the twin objectives of environmentally friendly MSW disposal and generating renewable power.

Located in the heavily forested country of Finland, the Kaukaan Voima biomass-fueled power plant produces process steam and electricity for UPM’s Kaukas pulp and paper mill as well as electricity and district heating for Lappeenrannan Energia, a city-owned power company. Launched in 2009, the plant can provide 125 MW of electricity, 110 MWth of district heat, and 150 MWth of process steam thanks to one of the world’s largest wood-fired fluidized bed boilers.

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In 2010 investment in wind power continued to accelerate, particularly in California and Texas. California also entered several solar projects in the race for financing. The finish line that renewable power developers and their partners are racing to meet is a December 31 deadline to qualify for federal cash grants.

Biomass energy has been an up-and-down industry for decades. As public awareness grows, it inevitably influences new tax legislation and environmental regulations. Two recent events have made the climate for development of this renewable resource even more volatile.

The University of California, San Diego has been accumulating awards for its savvy use of a constellation of power generation and energy-saving technologies. The campus already controls a fully functioning microgrid—including a cogeneration plant—and, as befits a research institution, is constantly looking for new ways to make its energy system smarter. This “living laboratory,” as campus leaders like to call it, demonstrates what it takes to build a smarter grid and why the effort is worth it.