I have a question that some of you might be able to shed some light on. As well as having an interest in biofuels, I also have an interest in Third World development issues and other technologies, including Solar energy collection and storage. So when trying to find an 'energy solution' for a remote village for example, there are a number of possible options. Of course, you have to ask, "what problem are you looking to find a solution for?" For the purposes of this post, I will assume that we are trying to provide electricity to power refrigerators, lighting, miscellaneous equipment such as telephones and computers (even remote villages can have satellite connections to the internet these days!). This would be a light load and not include industrial use nor electrical heating/cooking.
So I will propose two solutions, both of which are used in various places: 1) Grow an oil crop, use it to power a diesel generator 2) Install photovoltaic solar panels and use a battery system to store the energy overnight Now I'm trying to get an understanding of the pros and cons of these two approaches, and which would be better for a particular location. The issues I have thought of so far are the following: -- Photovoltaics and batteries are expensive in terms of capital outlay, whereas biofuels are cheap to 'install'. Photovoltaic systems have a conversion efficiency of ~10% of the solar energy, whereas biofuels have a conversion efficiency of about 1% Photovoltaic systems require more specialist knowledge to maintain, whereas biofuels require less. Photovoltaics require low labour input once they are installed, whereas biofuels require planting, harvesting, processing etc.. Photovoltaic systems can store only small amounts of energy over short timescales, whereas you can store large quantities of oil for a long time Photovoltaics make less sense when sunshine levels are highly unpredictable, whereas biofuel crops are not significantly affected by a few gloomy days Photovoltaics require less land to install than oil crops, because of their higher conversion efficiency. -- I realise that this is an oversimplification of the issues, and I'm trying to gain a deeper understanding of the secondary issues. So my specific questions are: 1) What are the implications of manufacturing Solar collectors, batteries, electronic control equipment and so forth in terms of energy use, toxic materials (e.g. lead in batteries), sustainability? How does this compare with manufacturing a diesel generating system? 2) Biofuels are often produced from crops that are grown in an unsustainable manner. What are the effects on biodiversity of this? How can this be counteracted? Are there any comparable environmental issues in the manufacture of solar systems? 3) Do the levels of expertise required to install and maintain a solar system make it inappropriate for use in remote villages? 4) Am I correct in assuming that the best (cheapest over all) solution for a Diesel generator in such situations is to use SVO (straight vegetable oil) with a preheating system, rather than converting it to biodiesel? 5) What are the effects on electricity usage patterns for each type of supply? For example, if people know that their battery system can only store a fixed amount that won't be replenished until the next day, are they more efficiency conscious than if they know their supply won't be replenished until next year's harvest? My gut feeling is that due to the higher conversion efficiency of solar panels, these would make a better overall solution for providing electricity than growing biofuels, with less environmental impact overall. However the high capital cost may rule this solution out for smaller villages. (Of course if you are using the energy for transport, then biofuels are much better because the energy can easily be stored and transported over long timescales. But that is not what I'm interested in here). Does anyone have any other information, opinions, experience of these types of systems? Have I overlooked any significant arguments on either side? I may soon have an opportunity to visit a remote solar installation that is backed up with a Diesel generator (as far as I know using petrodiesel) so wish to find out as much as possible beforehand. Regards, Donald ===== -- 43 - slightly more than the answer to life, the universe and everything. ___________________________________________________________ALL-NEW Yahoo! Messenger - all new features - even more fun! http://uk.messenger.yahoo.com ------------------------ Yahoo! Groups Sponsor --------------------~--> Make a clean sweep of pop-up ads. Yahoo! Companion Toolbar. Now with Pop-Up Blocker. Get it for free! http://us.click.yahoo.com/L5YrjA/eSIIAA/yQLSAA/FGYolB/TM --------------------------------------------------------------------~-> Biofuel at Journey to Forever: http://journeytoforever.org/biofuel.html Biofuels list archives: http://infoarchive.net/sgroup/biofuel/ Please do NOT send Unsubscribe messages to the list address. To unsubscribe, send an email to: [EMAIL PROTECTED] Yahoo! Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/biofuel/ <*> To unsubscribe from this group, send an email to: [EMAIL PROTECTED] <*> Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/