ALGAE ENERGY
I like hearing of ways in which some of our pollution problems are solved by new technologies, particularly ones, like hydro-power, that use the power of water. Also, we hear so many negatives about what is happening in the environment and to conservation efforts that I like to inform you when progress is being made. I can assure you things are so much better than in my EPA days, early 1971. At that time rivers where catching on fire because there was so much pollution!
An effort is underway in Venice, Italy to harness the bio-energy potential of algal life. Researchers on a tiny, thin strip of land, the Island of Pellestrina, hope to power the city’s entire port by harnessing the bio-energy potential of algal life. They are busy identifying which of the lagoon’s native species of unicellular micro-algae can be bred in new bioreactors to provide efficient biomass for electricity and motor fuel production.
Set to be operational soon, the experimental tanks will generate 500KW of peak capacity with oil derived from algal pulp. ( A medium sized car engine is rated at 50 to 150 kilowatts. If cruising, half that amount.) If successful, the project can be rapidly scaled up to 50MW. (A typical coal power station produces around 600-700 megawatts.) The entire port currently consumes 7MW. This is one of the growing number of projects extracting bio-fuel from algae. These simple organisms offer a slew of advantages. They can be harvested as often as once every three days, have higher oil content than alternative biological sources, and since they can grow in tanks, they reduce the risk of ecosystem damage and do not pinch increasingly scarce arable land as other biomass crops do.
Then there is the technology’s apparent carbon neutrality. So far no full life-cycle energy assessment has been undertaken. But, goes the argument, since algae can absorb carbon dioxide, the process is probably sustainable.
Yet despite broad support, scientists do not agree on whether the process can actually generate any useful energy to be used world-wide. To achieve the abundant algal growth necessary, a substantial amount of water, carbon dioxide and fertilizer are required. The costs of these, combined with the energy used in harvesting and drying the biomass, means that any net energy gain may be nugatory. Still it remains a possibility for smaller scale efforts. Perhaps, these efforts should focus on local solutions rather than universal solutions. What works in a dessert is unlikely to work in a rain forest (such as solar power).
