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Renewable Power thoughts
I recently had PV Solar power installed and was struck by the potential of this technology for providing most of my electricity needs. Unfortunately, a couple of issues thwart this goal:1) Supply-side issue: In the UK, the supply of power from the panels varies dramatically throughout the year with peak supply in June/July and a low in Dec/Jan. Further, during the day, the voltage from the PV panels varies from a low at dawn/dusk through to a peak somewhere near mid-day (and basically zero at night!). So, the power generated has significant daily and season variability.2) Demand-side issue: With the household mostly unoccupied during the day, the peak demand for electricity is in the evenings, when the PV system is not generating much if anything. This is when the power hog devices like washing machines and power showers are run. So, much of the generated power goes unused and is fed back into the grid (at 3p / KwH export rate).So there is not a lot you can do about the seasons/rotation of the earth and unless we change our work habits it is unlikely that we’ll spend the day at home most days. Still, a few ideas came to mind for possible opportunities for new technology etc.1) Power storage for smoothing out demand/supply variability: Some kind of energy storage system would seem ideal here -but batteries of any notable capacity seem prohibitively expensive. There were internet articles about using kinetic storage e.g. rotating flywheels to store energy. I wondered if elastic potential energy could be used e.g. an uber-clockwork generator.2) Saving money through saving on heating costs: Although we use gas for central heating, there were a few articles on using the electricity to power storage heaters (like the Economy 7 storage heating systems) – this could be interesting if it were possible to get a small/portable storage heater that could be run on a timer. Others had talked about using a low wattage immersion heating element on a timer to heat up a tank of hot water during daylight hours. This one could be feasible although a challenge is not having a closed loop control system that monitors the PV generation rate – on a cloudy day, much of the power for the immersion heater might come from the grid at full cost rather than the PV array.3) “Power me to make money”: so a slightly random idea is having an application that makes money just by being powered. A bizarre example might be an electric loom that churns out fabric when it is powered. This could be powered during the day when the electricity is ‘free’ with the fabric produced being sold when a large enough batch has been produced. If this concept could be applied to a web service it could be very interesting although nothing immediately comes to mind. The power cost of running a PC is pretty low so one would expect that it would be economical to run it on-grid if the output produced was worth more than the power cost.Since the original article was published, Crypto-currency mining has emerged as an obvious way to make money by just applying power… albeit with some significant Pros and Cons. I’ve written a longer article on this topic.4) Electric Cars: I like the idea of electric cars for vaguely green reasons but with solar power during the day, a car could be charged at home for part of the day at a lower cost. As there are at least 4 days a week when someone is at home for us, this could allow for sufficient charging occupancy during daylight hours to use most if not all of the PV power generated. This would require some research though to see if the power required is not too high and how well the batteries would last up to lots of short recharge cycles. With some battery lease schemes available e.g. the new Renault one, the later might not be as big a concern to the consumer.A side-note on electric bicycles… these are getting a lot more popular (In the UK you can find many models here in the USA this link has more details) – these take a lot less charging/power than electric cards and are even more environmentally friendly. You could quite easily charge up a 12V battery from the PV power supply during daylight hours and then charge the eBike up when you are back at home after hours.The elephant in the room – FITS:Of course, the basic economics of the PV array to provide all your electricity needs today do not stack up in isolation. The current government incentives for micro-generation i.e. the feed-in-tariff subsidy is the main hard economic benefit – at 43p per KwH generated + savings on electricity purchased from the grid the system we installed will have a payback period of about 6 years and then continue to pay-out the FITs income for the remaining 19 years.So to wrap up, what thoughts for opportunities for new technology?1) Energy storage systems e.g. elastic potential/gravitational potential (a la reservoir pumped storage) on a small scale.2) Battery powered devices that have software/hardware that allows for recharging at specific times of the day. A clever computer controlled timer plug with a connection to a web-service connected to the PV array to determine when to switch on would be interesting.3) Cheaper and safer storage heating systems, preferably portable.4) Cunning new revenue generating ideas that only require power to be applied to make money.3 responses to “Renewable Power thoughts”
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An interesting blog with info on using Solar PV panels to power an electric car: (US based) http://solarpowerelectriccars.blogspot.com/2012/01/everything-is-going-according-to-plan.html
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Was wondering how much the G-Wiz electric city car was (as featured on Top Gear with Clarkson driving it) – 12K new, or 9K second hand – 48Mile range, 10KwH to charge fully – interesting but suspect that most of the power would have to come from the Grid as the PV array would not deliver sufficient power most of the time the car would be plugged in. Desperately need some sort of power storage system to allow for demand matching. http://www.goingreen.co.uk/store/content/lovegwiz_gwiz_information/
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Hijacking own comment thread with stuff about electric/hybrid cars! This is a handy UK site: http://www.nextgreencar.com/ new plug-in hybrid Prius looks good – 14miles on EV, that would be enough for school run.
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