pranabjyoti Posted June 8, 2009 Report Share Posted June 8, 2009 At present, both efficiency and output of solar thermal power plants are quite low and it's a big reason behind the high cost of kWh electricity produced in present day solar thermal power plants. The other reason is the high cost of maintenance of array of reflectors. But, this cost can be reduced to less than 1/3rd of the present day level. The way is using atmospheric or psychometric heat along with solar heat. The way is very very simple. First, evaporate the water with the help of a vacuum pump in such a way so that the latent heat of vaporization of water comes from the atmospheric heat and then heating the vapor produced in this manner with solar heat. It can be easily calculated that in a steam at temp 300ºC produced in the same manner as that of present day thermal and solar thermal power plants; latent heat of vaporization of water is about 2/3rd of the heat consumed by water in this process. By vacuum evaporation of water, the latent heat of vaporization of water comes from the atmosphere and heating the vapor by array of solar reflector would need 1/3rd of heat necessary before. Therefore, with just 1/3rd of the amount of solar reflecting arrays, we can get same efficiency and output. I am just giving here a short zest of the idea here. Anybody interested, who is willing to discuss this idea with me, can contact me at pranabjyoti_calcutta@rediffmail.com. Link to comment Share on other sites More sharing options...
underling Posted June 8, 2009 Report Share Posted June 8, 2009 I've been looking at the air-source heat pump market for domestic applications for a short while, a market which incidentally has been slow to take off due to several reasons including the economic climate. Operating as a system to compete with ground-source heat pumps as a method for providing heating for properties it works in the same way as ground-source but draws the heat from the air rather than the ground and are quoted as being, as suggested in the previous post, 300% efficient with a requirement of electrical supply only to run. Should it trigger interest in anyone here one manufacturer in particular is able to supply this box at half the retail price of other more recognised alternative manufacturers in the UK and have had a long history of manufacturing oil boilers but I've also been trying to investigate whether there are any common patented component parts that exist within each manufacturers alternative. http://www.trianco.co.uk/activair.cfm There are disadvantages which are not obviously highlighted within the pitch as they are generally recommended for Underfloor Heating systems as they require wall hung radiators to be increased in size by approximately 20% due to their maximum water supply temperature so are not ideal as a direct replacement for a gas fired boiler, though they cost roughly the same as a gas fired boiler and should in theory cost less to install. Another disadvantage they don't shout about is that the fans can be a little noisy. I evaluate the air-source as a 'poor man's ground source alternative'. Also they have the added benefit of being wall mounted which means it is concieveable for them to provide the heating for multi-storey, multi apartment properties which makes them also a far more flexible alternative to ground-source and indeed solar. It surprises me that these units have had little media exposure (investment related?) and post this here merely to gain some alternative opinions on their validity both as a product and as an investment. Additionally ........ one of the most surprising things that are holding back their promotion is that heating engineers generally prefer to work with traditional natural gas boilers as air-source can be installed by a qualified electrician as opposed to a gas engineer and to a degree it is not in their interests to promote the installation. Link to comment Share on other sites More sharing options...
maelstrom Posted July 21, 2009 Report Share Posted July 21, 2009 I've been looking at the air-source heat pump market for domestic applications ................................................... One of the problems with ASHP is that it's just an air-con unit in reverse. Hence you need a large external fan to make it work. This may be noisy and it certainly can be unsightly. You need to be able to overcome the logistics of that before it becomes a ready sale for the domestic market. Gotta agree that 4u out for 1u in of energy is a pretty good economic proposition. If you've got any more thoughts on that - please update Link to comment Share on other sites More sharing options...
underling Posted July 22, 2009 Report Share Posted July 22, 2009 Absolutely right regarding noise levels of the fan which I can imagine is also going to need servicing/replacing fairly regularly but I have witnessed quite a few new builds recently reducing initial outlay by replacing the initial plans incorporating ground source with air source. I would also point out that I seldom see either ground source or air source providing hot water for households in domestic housing plans, it's generally incorporated with underfloor heating. I would add also that I'm still investigating this technology and am not completely sold on it yet as a viable investment opportunity but from what I've discovered so far have to admit that it's fututre does look positive. Link to comment Share on other sites More sharing options...
underling Posted October 3, 2009 Report Share Posted October 3, 2009 Absolutely right regarding noise levels of the fan which I can imagine is also going to need servicing/replacing fairly regularly but I have witnessed quite a few new builds recently reducing initial outlay by replacing the initial plans incorporating ground source with air source. I would also point out that I seldom see either ground source or air source providing hot water for households in domestic housing plans, it's generally incorporated with underfloor heating. I would add also that I'm still investigating this technology and am not completely sold on it yet as a viable investment opportunity but from what I've discovered so far have to admit that it's fututre does look positive. To update ........ have discovered that many of the cheaper range of air-souce heat pumps currently being sold in the UK are suffering from problems that our climate presents them with. The units in question are generally Czech made and after a year or so of use are suffering because of the damp winter conditions and humid summers. When drawing heat from the air, water which has condensed onto the heat exchanger freezes and the heat pump then reverses to defrost. Instead of creating constant heat they instead fluctuate between normal and reverse cycles thus their efficiency is adversely affected. There are some companies which have been producing heat pumps for the UK market who's product is far more robust and suitable for the UK climate and my souce of information is predicting major problems with the cheaper models in the very near future. Still ........... the repair and maintenance companies should do well. Link to comment Share on other sites More sharing options...
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