Grand Challenges for Engineering - Jan 05, 2009
The cost of solar energy is dropping. But how low must it go for it to be widely used around the world? How much more are we willing to pay for a greener energy source?
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The government needs to push this more and start to push it on car companies and energy producers, they have spent too much time idiling around.
The biggest mistake that we all do regarding solar energy is that everybody advertising the ecological profile of this technology. Of course this is the most important aspect, but in reality when it comes to the application, nobody cares how much green it is. Economics is what matters. The further step that solar must achieve is a competitive average (since irradiation varies) price against oil in terms of $/kWh. The problem is that oil price changes from time to time so nobody can estimate exactly what this $/kWh should be. However in order to make solar energy cheaper the only way is large scale production of solar modules, wafers, cells and most imporant polysilicon. Feed in tariffs can help a lot to this direction.
Dear Sr. It's time to change from volt-cell matterial to increase more than 31 % of solar energy obtained . i know that you must cost a lot of money but if you find some good first you will have the prize and the worlds thanks to you. I'm a foreign bachelor chemical engineer I'd like to make something but It's in miami nothing important so i must move to the investigation company area ... thanks for you time have a good day diego paz diegopaz100@hotmail.com
At present the cost of solar energy may look high comparitive with conventional energy. All engineers, world wide have to spend at least One hour per day for finding out the solution how to reduce the cost of solar energy production, defenetly can be achived. when sloar energy is made avilable at afrodable price to common/poor man, people start using solar energy insted conventional energy. I can cote an ex. here, In the initial stage the cell cost is too high to purchase by a common man, as compitation increased in manucturers the cost slassed down. Same way due to the problems facing by the present conventional energy avilability, people start using Solar energy. and if prises slashes down further usage will increase. In the present senario, Govt. has to impose a rule on MNCs & Other Govt & Public industries to use solar energy at least 10% of their requirement. Then only compitation increases in the field of manufacturing at low price and public will start using the same like cell phones.
we need solar energy in our daily use. if cost affortable we can save globle threat of envormental disturbances, there by saving earth and mankind
capture heat from the sun to create a heat exchanging hot water heater. If 75% of the USA used heat exchanging technology to heat water, when they could, how much energy and money would we save? How affordable is this technology? It is black aluminum or copper tubing with water connected to an insulated tank; the tank has a coiled tubing running through it with cold water in and hot water leaving as it is heated in the tubing coil. I have heard these things get so hot that anti-freeze coolant is needed to keep the water from boiling. How do you measure 'affordable'? What means are there to provide incentives? I think it would be inexpensive to install this device on most sites but I think people are too busy to bother to investigate. Incentives or penalties are probably the most effective way to get people to get things done (or lose a local election ). For your living space- store heat overnight in a room or rooms in your building that have many windows, made of black bricks that can retain heat, and has windows or doors that allow the heat into the other parts of the building during the night or cold times. These rooms can hopefully retain heat during the day and give off heat during the night. Maybe some heat exchanging tubes can supply heat by being built into your flooring and turned on and off with a simple valve that allows the hot water through the circuit. Now you need to store the suns energy for light and electricity to run motors and stuff? That would be convenient eh? Perhaps you can use wind or wave power for the other uses like running my computers and my hair clippers. I think you would save much power by using passive heating. Can I cook food using passive heating? That is what I would like to be able to do- and do it with rudimentary technology.
If every roof in Florida had solar panels and our meters could run backwards to the grid that might provide the incentive to mainstream solar energy production.
Solar thermal already reaches efficiencies of up to 40%. Power storage is essentially a solved issue, and the technology has been put into production world wide. http://news.cnet.com/8301 -10784_3-9775824-7.html http://news.zdnet.com/210 0-9595_22-6166113.html http://news.cnet.com/Full -steam-ahead-for-Nevada-s olar-project/2100-11392_3 -6166113.html
Solar energy is already practical and economical today. Here is why. Often from an econmic perspective people measure the cost of wdigets from a production perspective. They leave out some costs that to them seem indirect to the prcoess. For example, we routinely hear about nuclear electricity being the cheapest to produce. But the cost does not include the 15 years environmental impact studies and attendant battles nor does it include the cost of decommissioning the plant after use. What would be the price solar electricity if large swatches of the American Southwest were layed out with even the current technology of solar. What if the UN would ring the world with a solar electircity belt comlelte with "inefficient" solar panels and highly efficient solar tehermal plants. I think the cost would be offset by the retirement of the current polutting technologies that currently damage our world and would reduce the cost of reversing the damage. In other words the true cost of the process should also include the effect of the result. When we include the overall costs (such as pollution from coal and nuclear) solar looks mighty cheap and we haven't even discussed the reduction of armament production since we would not have to fight each other for that last drop of oil.
Solar thermal electric technology can store heated fluid and generate electricity 24 hours per day. According to a paper by Nobel Laureate Carlo Rubbia (delivered at the 2006 SolarPACES conference in Seville, Spain), a mere 15 000 square kilometres of land in the sunbelt will produce an AVERAGE power of 1000 GWe -- which is about (or more than) what the US uses now. I believe Rubbia refers here to Linear Fresnel Concentrators -- which has not been as widely used yet as parabolic trough concentrators, but will see some 400 to 800 MWe in California soon. For parabolic troughs and central receivers the land used will be 40-90% more, depending on what variant is used & how closely the mirrors are spaced. Yet the land needed to supply the US or the world with secure clean electricity in abundance is tiny. And NREL projects its cost to drop from the present ~ $120/MWh to below $50/MWh within a decade -- which apparently is below the cost of new coal (not to mention clean coal). The cost per MWh of solar thermal electric is far below the best Photovoltaic, has been for decades, and will probably remain so. Is it wise to give so little attention, and so little priority to improving and effectively promoting this and other clean energy technologies, to minimize CO2, mercury . . emissions that threaten our climate, our health and our future? I fear that our generation will be judged harshly for not doing so. Instead money is spent on oil wars that serve no purpose other than impoverishing Iraqis (and the US) and strengthening Islamist radicals & regimes.
Dear Sirs, Just take a look at this: http://www.nrel.gov/analy sis/forum/pdfs/2003/summa ry_03.pdf http://commonhorizon.blog spot.com Thanks, Gonzalo
I believe new emerging solar cell technology like dye solar cell and polymer solar cell will make solar energy cost effective in near future. However, conventional fuels may not be completely substituted by solar/wind/geothermal technology, what we can expect will be a hybrid of renewable with fossil fuels.
"...research should not be limited to photovoltaics; other methods of utilizing solar energy should be explored."
The current cost of photovoltaics is too high for their large scale implementation in the third world. Moreover, the technologies and skills required to manufacture components for photovoltaics are also rare in these regions. The first step should be establishment of the infrastructure required to make mass production of photovoltaics possible. This will be best done through global outreach programs and multilateral funding. Yes, research should not be limited to photovoltaics; other methods of utilizing solar energy should be explored. One such method is to heat water to steam and then to store it in pressurized caverns underground, and then using it to turn the turbines. Another method can be the concentrated solar technique. These methods will work optimally with efficient heat exchanging systems, so research should be focused on them. If all of these solar opportunities are explored and implemented to complement one another, the overal long term cost of solar power may be brought with in the range of the third world's kitty.
I think a discussion of solar energy should include the solar thermal generation technologies that are currently more cost-effective at large scale than photovoltaics.
Cheap energy will make automated trashcans possible!
Solar Energy? For me I should say YES! But how? I want to learn about Solar Energy and Wind Power. The Philippines is a tropical country so it is ideal here. But this is expensive here and very little information about Solar and Wind Power! Thanks!
It was great to know that efficiency of some of experimental solar cell have reached 40%. 87,100 TW is the amount of sunlight that falls on the Earth's surface, 370 TW is all the energy in the wind, and 15 TW was the global rate of energy consumption in 2004 (source :- wikipedia) . Difference between energy from wind and sun is straight forward. I hope one day will come when every house will have solar roof. Even plane, train, etc. could be running on solar power. But what remains Question to me is Cost-Effectiveness and efficiency of solar cell in coming period of time. If any one wants to share information about solar power/energy/production do let me know. As a student, I am very much interested in knowing more about solar. mihir.shingala@yahoo.co.i n
At first I would like to say that, sir this the best source energy (IN THE SCIENCE AND TECHONOLOGY POINT OF VIEW) and specially for the middle class family. This project is go reapetedly in the rural area and I lastly say that govt should finance this project in the rural area
I used solar panels on my VA/FHA Four-plexes back in the mid 80's to heat water. The project was built to Gov. spec, however, I could not get the solar included in my appraisals at the time. I want to repeat that program now and want to go solar as much as possible. Is there VA/FHA approved solar for housing now and if so what is my best strategy to get necessary Gov. approvals and credit ? A well engineered project like this could gain a lot of positive exposure for the solar industry. Maybe one of your Solar Teconics would like to expose leading edge solar panels in a joint venture. We are also trying to go solar in another way i.e. Hydroponic (water) farming of organic vegetables both for consumption and, in the case of sugar beets, conversion to ethanol as a renewable energy source. In Texas we can do this perpetually in very large green houses by growing sugar beets which have an 85% conversion ratio.
I think we should review and revive development of amorphous silicon solar cells. They, according to me, still will be a cost effective alternative. I was involved in the development of a-Si cells for some time. Could produce 3 sq ft area modules - double junction- in a single chamber. Stability was good. Degradation compared well, too. Foe sustainable development, Solar (SPV) is an indispensable imperative.
For those of us old enough to remember: before the transistor and silicon valley there was the vacuumtube. Theyve got a bad reputation for their burnouts but we still use them daily in our microwave ovens: the magnetron operates at 65 % efficiency whereas a transistor would not reach more then half that for same purpose. In order to economize consumer solar electr. generation should the solar industry go retro? Thermionic electric converters (TEC) harness the whole solar spectrum with higher theoretical efficiencies of up to 70 %. Just the approach taken by Vanderbilt and Tufts univ. of engineering. (see also: advanceddiamond.com). With a 50 % lab efficiency and good radiation resistance, the goal here is 10 $ CENTS/WATT material, to be made possible by advances in IC mass-manufacturing and CVD nano-crystalline amorphous diamond coatings, either in the form of roof panels, or as cellular vacuumtubes, in conjunction with cheap CSP-devices hooked up to open source sun-tracker software. At that price who wouldnt go solar? But regardless the outcome of this, until silicon valley produces the perfect multijunction solar cell, matching the solar spectrum from a single alloy, TECs will play a future role. Perhaps our blue chip giants, with their economies of scale, could reverse-engineer TECs, make solar go more mainstream and restore some of their old glory. (Oh and while they do that, could they please phase out the incandescent lamp for (O)LEDs? It would save 20 % of worldwide electricity use-an annual production of about 268 coal-fired powerplants. Edison would no doubt be quiet happy to see the positive effects of (t)his).
I think continuous thin film production is the best approach to drive down the cost of photovoltaics, which could be mounted on roofs with local battery or flywheel storage. The latter is also useful for wind and other intermittent sources. Solar thermal plants might be worthwhile in the Southwest, and potentially can operate as baseload plants by storing heated liquid in large tanks during the day for power generation at night.
My photovoltaic solar stack would use a lens to concentrate sunlight into a beam that would be injected into an illumination tube to stimulate the gas to generate light that would shine on solar cells that are arrange in a hexagon. A solar stack assembly could be made up of thousand or millions of stacks. They wouldn't be as efficient as a flat display on the surface. But since most of the stack is below the surface and even at 1/3 efficiency, more electricity could be generated, the stack would be better than a surface display. My latest solar stack would be the solar steam stack. It would use a lens to concentrate sunlight into a heat beam that would strike water tubing to create steam. The steam would run a turbogenerator to generate electricity. There could be thousands or millions of stacks each producing steam to run generators. If each generator produced a kilowatt of energy, multiply them by the number of stacks used. Storage of excess energy could be in stacked flywheel units. They would be sealed and the motor/generators between the flywheels would be liquid or forced air cooled to prevent vacuum leakage. There could be two motor generators sandwiched between the flywheels that would be made from either rock quartz or one of my ultra-stressed crystalline molecular solid materials that would have magnetic bands around their circumference that would face magnetic bands in the chambers to produce a linear induction effect. My goal is for the flywheels to store at least 100 watt-hours of energy kinetically safely. As one flywheel is being respun up to speed, the other might be producing energy with the second motor/generator. In space, we should use induction coils to use the charged particles from the sun's solar wind to produce electricity. The electricity could be beamed down to earth either as microwaves or a small injection reactor might be used to produce a carrier beam that would ionize the air and allow the transmission beam to reach a surface station without loss. Solar steam might be more economical and practical than solar voltaic. Even gas cycles that would produce steam on the surface and condense below the ground to run turbogenerators might be part of the answer. I counting on the stacks to possibly be what we need for large-scale solar electrical production.
It is not just the cost, it is about how many people are willing to switch to this kind of energy without thinking of the space that can occupy or it aesthetic. The short-term cost is much, but in long-term it pays for itself.
I have been involved with solar energy engineering for much of my career. For most of that time, the solar energy research establishment in the US has seemed like a dead hand on this R and D enterprise for decades. The tendency has been for the establishment to promote the same old well-favored or well-connected technologies like PV and disparage cost-effective technologies like DHW and SHCOB. This poor public-sector leadership has tended to mislead private industry and investors into making poor choices. Part of the problem has been the natural inclination of well-funded science-oriented researchers to pursue merely novel if not necessarily useful paths just because this approach generates quick and plentiful reputation-enhancing publications. In addition, well-meaning engineers the national labs have too much involvement and influence with private industry, which discourages industry from working with independent researchers who might have some innovative and cost-effective ideas. There probably is a useful role that federal involvement could play, but the top down approach does not seem to work. A good first step would be for the national labs and especially NREL to stop competing with independent researchers and stop trying to pick winners in the solar derby. Many of those contributing to this page correctly point out that solar heat -- whether DWH, SHOB, or CSP - is more efficient and cost effective than PV. The DOE is enamored by high-tech PV and has diverted too much effort into that inherently limited field. This is an example of well-connected science-oriented researchers forcing the research effort into non-productive areas. DOE and NREL should step out of the limelight for a while and let some freedom of thought and cost-effective ideas flourish.
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