Green Engineering & Energy Efficiency in the USA - Case Study Example

Running Head: Green Engineering & Energy Efficiency Green Engineering & Energy Efficiency Institution: Student name: Date: INTRODUCTION Solar water collectors have been in the use from 1900 where they were being used in USA(John Perlin, Evolution solar) , where even lack tanks mounted on top of the roof was used. The first water heater was designed in USA by enclosing a tank with in a wooden box. Flat-water heaters were used as early as 1920s in Florida South California (Wikipedia.com, 2010) , the solar heaters become popular with the effect of frequent power surge in America in 1960 while the oil crisis led to more demand of the solar heaters. Flat-plates are expensive and heavy systems which require more than three people or even six to install. With the technological advancement, evacuated tube collectors were discovered and designed to overcome the challenges of flat-plate collector. Environmental considerations were put into mind while designing the ETC systems where materials that are less emissive are coated on the tube tubes (ren21.net, May 20, 2010). Spain as a country has been recorded as the second country after Israel in 2006 of making it compulsory to install solar water heating system (ren21.net, May 20, 2010). Evacuated tube flat plate solar collector (ETFPC), is a solar collector that functions differently from basic flat-plate solar collectors which were designed for using in high temperature climates. ETC has evacuated tubes which are fitted via dry manifold. The heat transfer is mainly achieved by liquid vapor phase materials which are very efficient. The materials used to make tubes are the borosilicate glass which is low emissive materials and having a selective coating on the tube enables them to be effective. Evacuated tube solar collectors are very innovative solar technology and it is also the most simple one where the basic principle is just like heating water in a plastic container on the sun. the production of evacuated tubes stated in 1980 by Quing Hua University in China(sunMaXXTM,, 2010) Evacuated tube systems work by heat transfer fluid (HTF) which circulates in a cycle. It circulates first through a manifold where it absorbs the solar energy captured the evacuated tubes. The HTF circulates to a water tank, where solar energy is transferred to the water heating the water. The HTF circulates back through the evacuated tubes where the cycle repeats. Design for Environment (Eco Design) life cycle assessment. The extent to which a solar system contributes carbon to the atmosphere is basically determined by the source of electricity. Pumping the fluid through the tubes by mains electricity is called a ‘low carbon solar’ (Martin and Watson, 2001). Cheap pumps which can operate with 1W and having a capacity to use up to 20W can be used to reduce the emission of carbon to the environment(lainginc.itt.com, 2010 ). There are various manufacturers around the world in coming up with alternative pumping systems which do not completely use electricity. The pumps which are based on the principle of thermal expansion and phase changes but the most important aspect in the this assessment of the life cycle is the evaluation of the cost incurred in acquiring the raw materials, in the manufacturing, transportation of the products, the usage the cost of serving the material and how much it costs in the process of disposing. The evacuated tube collector within having vacuum which is the best insulator to the environment which the Evacuated tubes utilizes therefore they are very efficient and cost-effective in all the climates even as low as -600F. The evacuated tubes are the one of the key in solar system which is designed in accordance to optimizing performance. The tube is made up of two centric glass tubes where they are fused together where each materials yields half of its content in a tube. There is an environmentally friendly external surface which is a selective layer making a solar power effectively usable. The external surface is used as an absorber of the sun’s radiant heat. There is a coating which is protected within the vacuum gap. The coating is an aluminum nitrite sputter layer which has low emission and it is a very good absorber. To conclude the cost of emission ETC systems constitute a small percentage in the life cycle cost and in most cases the cost is recovered within the first few years of usage. The environmental effects can be cautioned by using non-mains electricity pumps, reusing existing hot water tanks while eliminating antifreeze replacement in cold climates (Wikipedia.com, solar water heating). Using vacuum tubes are best alternative to using coal which burns and emits a lot of carbon dioxide. fig 1.0 fig 1.1 source : solarpowerbeginner.com Evacuated tube solar collector Recommendations for DfE For environmentally friendly ETC, the solar systems must be designed with tubes which are coated with aluminum nitrite supper layer . The coating is an aluminum nitrite sputter layer which has low emission and it is a very good absorber. Compared to coal burning as a source of energy, ETC is the better in terms of conceiving the environment hence the company can help reduce global warming effect with the cheap and effective designs of solar water hears. Life Cycle Design Evacuated Tube Solar Collector fig 1.3 Technology: ETC is a new technology, which is a hi-tech and has improved rapily recently, the products are being used and are very dominant in European and Asian markets. fig 1.4 Diagrammatic design of the ETC solar system Functionality of the system and economic analysis Evacuated tubes: Heat Loss Protection: The loss of heat is protected by the sealing of the vacuum glass such as Thermos bottle which is used to prevent convection and conduction heat loss. The method increases the efficiency of the system and also enables the system to be more reliable and cost-effective designs. Cost effective design comes in where expensive materials such as thermal sensors and controller components are not needed in the design. Existing equipments such as electric water heater can still be used as a solar water tank having few cheap external heat exchangers. With evacuated tube collectors there is no need to purchase another tank for fixing water temperature by mixing hot and cold water because it can heat water to very temperature and with an automatic tempering valve temperature can be fixed for instance 100o from the same tank hence saving money and having additional space for another tank. Durability and Reliability Evacuated tubes is durable and lasts for a longer period because the vacuum gives protection to the heater absorber surface from moisture, corrosion , degradation and condensation of the selective coating. There is no fluid that touches the solar collectors because water is transferred by heat pipe which is an efficient way of heat conduction and transfer with this design there are no corrosions and efficiency losses. The system is also very reliable where if one tube is damaged the entire system continues to function and the replacement of the evacuated tube can be done without stopping the whole process. A vacuum lasts for about 5 to 15 years varying from collector to collector.   Recycle & Reuse Ease of Installation and Service: It is easier to install evacuated tube collectors without an expert or special tools because the tubes, manifold, and frame can be brought onto the roof separately and assembled easily. Existing water tanks can be reused over a long period of time. Evacuated tubes lasts for about 5-15 years. The solar system can be reused by replacing the worn out tubes hence the system will still function. fig 1.5 Since the evacuated tubes are installed in the manifold via dry connection, any tube can be removed without shutting the system down. System cost Compared to other sources of energy like gases and electricity solar energy is free. The cost of solar systems vary from place to place depending on the latitudes, areas where freezing occurs regularly special devices are set to protect the solar system. It is clear that evacuated tube collectors are more effective in freezing locations compared to flat-plates therefore the cost of ETC is less the cost of flat-plate collectors in these regions. When analyzing the cost of a system there are various factors to consider which include; the initial price of purchasing the solar system, the cost of installing, price of electricity, the effectiveness of the system, the price of electricity per unit, annual tax rebates and the total annual maintenance cost. Below are tabulated cost estimations for various countries without considering annual tax and cost of installation. The payback period with a clear indication of the magnitude of time for payback and the total costs are indicated in the table. Having an assumption that 6.57 kW per day is saved because of the use of solar water heater ( Marken, J. Sanchez, 2008). Costs and payback periods for residential SWH systems with savings of 200 kW.h/month (using 2010 data) Country Currency System cost Subsidy(%) Effective cost Electricity cost/kW.h Electricity savings/month Payback period(y) Brazil Real 2500 0 2500 0.25 50 4.2 South Africa ZA Rand 14000 15 11900 0.9 180 5.5 Australia $Aus 5000 40 3000 0.18 36 6.9 Belgium Euro 4000 50 2000 0.1 20 8.3 United States US$ 5000 30 3500 $0.1158 $23.16 12.6 United Kingdom UK Pound 4800 0 4800 0.11 22 18.2 Source: Wikipedia.com, Solar water heating. Conclusion The consultant firm after analyzing the environmental impact of the evacuated tube flat plate solar collector (ETFPC) water heaters, its sustainability and the market recommends that Benign Energy Technology Solutions (BETS) should proceed with the plans of manufacturing the evacuated tube flat plate solar collector (ETFPC) water heaters products. This is in the view that these products unlike other sources of energy like coal and gases, it is environmentally friendly with CO2 to the atmosphere is managed by coating the tubes using aluminum nitrite sputter layer which has low emission. The cost of installing and maintaining the product is cheap where even one person can successfully install the solar system (evacuated tube collectors). The products can be shipped separately then assembled by the clients because there are no special tools or skills required to install and service the system. With the effect of global warming every country if concertned with coming up with an alternative source of energy for instance Spain in 2006 required that houses should be installed with solar water heaters hence a large market share. Evacuated tube collectors are suitable even in cold climate because of the vacuum tube technology hence the products can be sold even in cold climate countries. The evacuated tubes can last up to 5 to 15 years then they can be replaced easily by the users just like replacing a fluorescent tube for electricity light hence the products have a longer life span. References C. Martin and M. Watson. 2001. Side by side testing of eight solar water heating systems. DTI publication URN 01/1292. London, UK C. Marken, J. Sanchez. (2008) PV vs. Solar Water Heating: Simple Solar Payback. HomePower 127,40-45 G. Tsilingiridis, G. Martinopoulos and N. Kyriakis (2004) Life cycle environmental impact of a thermosyphonic domestic solar hot water system in comparison with electrical and gas water heating. Renewable Energy Volume 29,1277-1288 John Perlin , Solar Evolution The History of Solar Energy, California Solar Center US. "Laing D5 solar pumps can run off of as little as 1 watt.". lainginc.itt.com. http://lainginc.itt.com/LG-pump-DC-Solar-Pumps.asp. Retrieved November 5, 2010.  M. Souliotis, S. Kalogirou, Y. Tripanagnostopoulos. Modelling of an ICS solar water heater using artificial neural networks and TRNSYS Renewable Energy 34 (2009) 1333–1339 "Nominaties VSK Awards [Laing ITT Ecocirc pump nominated for prestigious VSK award in heating category]" (in Dutch). bouwwereld.nl. Retrieved November 5, 2010.  http://www.bouwwereld.nl/web/Actueel/Nieuws/Nieuws/08820/Nominaties-VSK-Awards.htm. "REN21 - Renewable Energy and Policy Network for the 21st Century". ren21.net. Retrieved May 20, 2010. http://www.ren21.net/globalstatusreport/g2009.asp.   Yong Kim, Taebeom Seo (2007) Thermal performances comparisons of the glass evacuated tube solar collectors with shapes of absorber tube. Renewable Energy, Volume 32,772-795 Read More