Algae are a wonderful product. In our company we produce algae on a large-scale as a feed for aquaculture and for human food additives. Because of their very special and very concentrated composition algae or phytoplankton offer unique and powerfull food supplements. A number of Marine Algae posess Omega-3-fatty-acids, all kinds of pigments, sterols, anti-oxidants and so, and so on!
But something that isnt possible with algae or any biomass for that matter is to produce energy or biofuels with a positive energy balance. Here im not talking about waste-stream biomass but specially cultivated biomass for the purpose of producing energy (bio-fuels). Anyone who is able to make a realistic! life-cycle analisisys will concur with this. The problem is, that the amount of energy from the sun in the form of photons that can be used by plants (Algae equal) is limitid to 45% of the spectrum (so called PAR-light), than there is a quantum limitation in the photosynthesisapparatus (8-9 photons are needed to bind one CO2 molecule) This kicks back the amounth of sunlight that can tyheoreticly be used to produce biomass to a mere 10%. In open ponds only 1-2% of the suns energy can be converted into biomass and in some other systems 4-5% and the practical maximum will be around 7-8%. This means for example in the Netherlands were there is 100 Watt/m2 available (year round) that you can only produce between 1 and 7 Watts per m2. This is less than the Energy needed to grow the algae (stirring of the pond/substrate, pumping, harvesting, utilitys, personel, transportation etc etc) Leading to a negative Mass Balance. Now people will say, yeah the Netherlands its alway raining overthere and not so much sun as on the equator or other sunnier places. This doent work as well, because to much sun/light will kill the algae and like humans algae have a limit in how much they can eat ( if I asked one of you to eat one hamburer, this would not be a problem, but if I asked you to eat 100 hamburgers this wouldnt be possible) Other problems that cost a lot of energy in sunnier (warmer) places are cooling (above 40 C most algae will perish), need for water because of evaporation, higher transportation costs (in terms of energy) etc. etc.
So the bottom line is: It isnt possible to produce energy if the production process uses up more enegy than that it produces.
With kind regards,
Sander Hazewinkel
LGem bv
The Netherlands
Propierty owner of one of the world's highest efficientie algae systems. |
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