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Renewable energy, such as from photovoltaic electricity and ethanol, today supplies less than 7 percent of U.S. consumption. If we leave aside hydroelectric power, it is under 4.5 percent. Globally, renewables provide only about 3.5 percent of electricity and even less of transportation fuels.
But increasing that fraction for the U.S.—as seems necessary for managing greenhouse gases, trade deficits and dependence on foreign suppliers—has at least three tricky components. The obvious one is how to capture the energy of wind, sun and crops economically. After that, the energy has to be moved from where it is easily gathered, such as the sunny American Southwest or the windy High Plains, to the places it can be used. And the third is to convert it into convenient forms. Most prominently in the last category, electricity for transportation has to be loaded into cars and trucks, either through batteries or perhaps as hydrogen.
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32 Comments
Add CommentStorage and transport of energy is the ultimate issue. Intrinsically, fossil fuels have no value, other than that they can be easily transported and have a high enough energy density to be able to be converted into something useful.
Reply | Report Abuse | Link to thisIMO, a distributed hybrid system of local or even personal energy production may be the ultimate solution. Certain uses in a home which are relatively low load and non essential, such as TV, computer, most lighting might be powered by solar and or batteries while other issues such as heat, cooking and refrigeration will use more conventional energy supply.
This would be accomplished by zoning the homes electrical system, in a similar fashion to how many homes today have zoned heating. Baby steps perhaps, but steps none the less.
The problem is, to make these sources competitive in price, either the government- through the use of our tax dollars- has to heavily subsidize these sources, or they put heavy fees on the other sources to bring them up to the price of these "renewables". Either way, when the American people are struggling to get by, it's only going to hurt us.
Reply | Report Abuse | Link to thisThere needs to be a plan that can ease us into better energy sources without further hurting American families, when they have less money to spend and everything is costing more.
Although I agree with the author's basic premise (increasing renewable energy production will be tricky/difficult), my energy statistics don't agree with what the author (Mr. Wald) has stated. I'm quoting from IEEE Power & Energy magazine, Nov/Dec 2008, P.104; and they show:
Reply | Report Abuse | Link to this1. Hydro - produces 6% of the total U.S. electricity supply (98,000 MW)
2. Biomass - produces 1.3% " (12,000 MW)
3. Wind - produces 1% " (21,000 MW)
4. Geothermal - Produces less than 0.1% (3,000 MW)
5. Solar - Produces less than 0.1% (No figure listed)
The question arises as to why Wind produces only 1% of the U.S. energy with 21,000 MW installed while Biomass produces 1.3% with only 12,000 MW installed. And the answer has to do with capacity factor. Although you have 21,000 MW of wind installed, the wind only blows strong enough to make the generators produce electricity about 30 - 40% of the time; therefore, (40% capacity factor) x (21,000 MW installed) = 8400 MW, or less than the 12,000 MW of Biomass installed.
This example also points out that the capacity factor (amount of time the generation unit functions) of wind and solar are also very important factors. This is in addition to the fact that transmission lines/pumped storage plants must be installed to convey the energy that is generated to where it is needed.
A low capacity factor means that you have paid to install additional energy generation, because it is not functional all the time (when you need it). This is another reason wind & solar are so expensive.
I take it you are an engineer or you would not be reading IEEE Power & Energy.
Reply | Report Abuse | Link to thisWhy use an unnecessary 3 zeros when you can simply change MW to GW?
The readers of this magazine all have scientific or engineering backgrounds. I support the globalisation of scientific units of measure and the use of standard prefixes for the same. I am not so sure of globalisation of trade, locally produced and consumed is energy efficient and reduces polution.
A ton of energy is spent just transmitting electricity through the power lines. If everyone where to create the power at their own homes with personal solar panels and/or wind turbines, it would fix the problem. Such a distributed network is the only safe way to go.
Reply | Report Abuse | Link to thisHowever, the trick is that the buildings must be built more efficiently. Current building practices are just plain wasteful. It is possible to build a home, for the same price as the average home, that uses less than 20% of the energy of an average home. That means that the photovoltaic/wind systems can be 80% smaller, making them more than cost effective.
The problem is that there are multiple compounding inefficiencies in the entire system. If they're not all addressed, then the solution won't work. The standard American "Throw-away-society" needs to come to an end. That's really all there is to it.
I am amazed! the commentors above, all seem to know something about the topic and are civil. I have been working on this total energy supply problem for over 40 years. I hope intelligent people can work together this time instead of loud conmen and politicians grabbing control and pissing away all of the money, resources and our efforts, as they have done over the last 30 years. The overall energy supply problem needs an over all mix of solutions. Not one at the expense of the others. Some are quickly doable others will take a more long term effort. A real continental coast to coast electric grid is essentitual. The greatest impediment to national energy solutions. Owners of present local and regional grids and pipelines prevent free movement of energy across their districts without high charges, often trying to trap low cost suppliers for themselves. All of this requires many minds and hours of discussions.
Reply | Report Abuse | Link to thisSaved energy = no CO2 produced
Reply | Report Abuse | Link to thisUSA electricity consumption peaks during summer, because air-conditions are used to cool the houses.
In European nordic countries the electricity consumption peaks just now during the cool winter time - to heat the houses.
In the nordic countries there is a strong shift toward using heat pumps (= air condition backwards), where the heat is taken from a hole drilled into the ground some 450-500 feet deep, and the stable temperature down there is utilised as the energy supply. This typically reduces the electricity consumption by a factor 3-4, depending on the heat-pumps efficiency and temperature difference. The ground temperature in northern europe is typically ca + 7C all year round, and by just circulating that temperature to the house during the summer a strong cooling effect at almost no power consumption (only eg a ca 50 W circulation pump is needed) is a quite nice byproduct..
In almost all areas of USA the ground water temperature (or the rock temperature, really) is sufficiently low and should be possible to use as a low-temperature source during the summer. Exceptions would be the very southern parts eg Florida where the ground temperature may in some locations be as high as 77 F, but even then, when connected to a heat pump the ground as the low-temperature source will make the heat pump much more efficient compared with an air conditioning unit that uses ambient air as the low-temperature source.
In Scandinavia drilling a hole (commonly 6 inches diameter) costs ca 7 USD per foot when you drill 4-500 feet, and a ground heat based heat pump - taken from the shop shelf - of the most modern and efficient type commands ca 10 000 USD.
This might seem like quite a costly investment for a one-family house, but the payoff is usually in scandinavian environment ca 3-4 years only, based on reduced heating bills, be that oil, electricity (direct heating) or natural gas.
By using ground heat for cooling in summer, USA could actually reduce or even eliminate the peak electricity summer demand. and thus the existing electricity grid might be less at peril to overload and emergency cut-offs. The private investment in ground cooling/heat might - provided the sitting administration so decides - be wholly or partially payed for with tax money subsidies, which would be a better investment for USA environmental future than strengthening the existing electricity grid at a similarly high cost...
Too simple ?? Google eg NIBE or IVT to find products in Europe..
scientific earthling
Reply | Report Abuse | Link to thisI use MW rather than GW because that is the most commonly used suffix for power plants. Very few plants are built in the GW range; and when we built plants the plant power output was "never" expressed as a 0.1 GW plant for a 100 MW plant either in the technical literature or in the engineering texts. In addition, many hydro plants (run of river and other small hydro plants) are in the 25 MW or below category; and expressing their power output in GW would be ridiculous.
Therefore, in summary, MW (Megawatts) is the common expression used amongst consultants, engineers, and contractors that build power plants. GW (Gigawatts) is not commonly used.
Nathaniel
Reply | Report Abuse | Link to thisCreating power at your own home via wind or solar means that you must have some type of energy storage system in mind. Most present day individual energy storage systems rely on batteries, which are expensive, inefficient, and have a short life (10 to 15 years). Consequently, most home energy systems(wind and solar) are too expensive to install Initially, and have high maintenance/replacement costs (batteries), which the average homeowner can ill afford. Until you can arrive at a more suitable energy storage system, I am afraid home energy systems on a "large" scale will not be an effective solution. Do you have a better energy storage system in mind? that is presently available?
What about systems such as those being experimented with in the Silicon Valley area, where any excess power generated is fed back into the city's power grid. In most cases though, my understanding is it's a null factor, since usually solar panels on individual buildings are only able to generate a percentage of the total needed at any given time. It eliminates the entire question of energy storage.
Reply | Report Abuse | Link to thisI the citizen of Russia.
Reply | Report Abuse | Link to thisExcuse please that I do not know nasty words on English.
I would apply all them in relation to the misters from imperous structures, ecological offices and enterprises, where make the equipment for generation of the electric power.
To me has bothered to write the letters in all instances that the way of transformation of a thermal energy of an environment in an electrical current is open.
The fragment converters is made and he works strictly under the formulas.
It is necessary to expect, that with application of this opening, the panel of thermal converters of equal cost and areas with the solar panel will give out in the afternoon and night not less than 100 kw of an electrical current.
To all chiefs laziness to learn details, or all such stupid?
Or at you, as well as Russia, the chiefs are not able to read the letters?
Juriy vetto@nm.ru
David M. Clement,
Reply | Report Abuse | Link to thisSure refer to a 10MW or 100MW for generators in that range perhaps even a KW generator for something in your garage. However in your table every single entry is in the GW range, why use so many zeros? Just for conventions sake? Just does not make sense. You should write for the reader.
arrons............ Grid tie photovoltaics have been in use for about 30 years, against the law until a few years ago. 1/4 of the roof of a house will generate more electricity then the house will use. It will cost about 25% of the cost of the house's construction cost. About $30,000 over $120,000. NO! storage.
Reply | Report Abuse | Link to thisStorage will cost as much as the collectors. the voltaic collectors only require occasional cleaning and may last as long as the house at least 40 years or longer no one yet knows for sure as they have only been using them for 30 years. Storage batteries only last at best 1/4 as long. The better and more expensive the longer they last. With grid tie the power company is the storage. I hope this helps.
Question.
Reply | Report Abuse | Link to thisYou would buy the converter of a thermal energy of an environment in an electrical current, if he cost 1000 US dollars and round the clock would give out 20 kw of an electrical current, and fuel would not consume?
Such installation would have the area of the panel of 0.2 square meters and fan by capacity 300B, which blows in this panel.
I recently read an article about so-called Gen IV nuclear reactors which use spent nuclear waste as a fuel and produce minimal amounts of very short lived (hundreds of years) very low level radioactive waste themselves. Great idea if it's real. Clean up our back yards, nothing left for terrorists to mess around with and fuel for the next 50,000 years. Looks to me like the end of the oil age.
Reply | Report Abuse | Link to thisRemember, the Stone Age didn't come to and end because of a lack of stone. The Oil Age will be no different.
faderullan:
Reply | Report Abuse | Link to thisFor the past 6 years I have had a ground-source heat pump for doing all of our space heating and an air-source heat pump water heater for doing all of our water heating. We have solar electric (PV) panels that produce as much energy in a year as we use. We simply dump electricity back to the grid when we have excess. This works find for us. However, if many people did the same storage would be necessary to deal with the time mismatch between generation and use. Some technologies that I have research are heat and cold storage. Cold (ice) storage is mentioned in the article. Small-scale heat storage is not. Some possibilities for heat storage are hot water and paraffin.
Successful PV automation, then a rather low but nationwide fed in tariff should do the trick of adding 15 to 20 percent solar to the mix. Of course the storage problem is that limiting factor. CSP (with large molten salt reservoirs) can provide 80 to 90 percent! Of course, a lower feed in should be enabled for that and wind. All feed ins should expire when fossils dwindle down to about 40% as fossils provide a cheap base rate.
Reply | Report Abuse | Link to thisThis is why I do not believe in heavy carbon taxes!
For example, If 1/5th of the mix is solar powered (with a feed in that degenerated down to twice the normal average, say 22 cents), and 2/5ths came from CSP (with a feed in that adds just a few pennies, say 15 cents total), then in this case, (with 2/5ths conventional costing 11 cents per kWh), you can see that it would only cost about 25 -30% more. As the tariffs expire, these techs should be cheap enough to be developed "all the way" to 80 or 90 percent. The existing RE base now would be cheaper since only maintenance is required.
Successful PV automation, then a rather low but nationwide fed in tariff should do the trick of adding 15 to 20 percent solar to the mix. Of course the storage problem is that limiting factor. CSP (with large molten salt reservoirs) can provide 80 to 90 percent! Of course, a lower feed in should be enabled for that and wind. All feed ins should expire when fossils dwindle down to about 40% as fossils provide a cheap base rate.
Reply | Report Abuse | Link to thisThis is why I do not believe in heavy carbon taxes!
For example, If 1/5th of the mix is solar powered (with a feed in that degenerated down to twice the normal average, say 22 cents), and 2/5ths came from CSP (with a feed in that adds just a few pennies, say 15 cents total), then in this case, (with 2/5ths conventional costing 11 cents per kWh), you can see that it would only cost about 25 -30% more. As the tariffs expire, these techs should be cheap enough to be developed "all the way" to 80 or 90 percent. The existing RE base now would be cheaper since only maintenance is required.
Great ideas are being developed. Geothermal is certainly a good idea. Combined with a radiant hydronic cooling system we could do a lot to reduce our electricity consumption for air conditioning. My groundwater temperature in sw Florida is 78 degrees F in the summer. How about a pv-powered chiller to cool that groundwater a bit more to cool our buildings?
Reply | Report Abuse | Link to thisThe issue of storage was mentioned. Storing energy in the way it will be used is more efficient than converting it to electricity and then back to cooling. Some European solar heated homes have a tall insulated water storage tank in the middle of the home to store the day's heat for use at night. We could do the same to store the day's coolth for cooling at night.
Night sky radiant cooling of the water is also a fascinating idea.
I also recently read about flow batteries:
http://www.memagazine.org/backissues/membersonly/oct05/features/rerere/rerere.html
Here is a smaller version:
http://www.cellstrom.at/FB10-100.56.0.html?&L=1
There are a lot of great possibilities that need to be combined in a hightech home or building. I'd love to find a builder open to developing such buildings with the things I have learned.
I hate the idea of taxing "carbon" use. Subsidizing noncompetitive energy sources prolongs the period of time that it takes to make them economically viable. Real competition is needed - a level playing field. Subsidize research and development - not the end product.
Reply | Report Abuse | Link to thisThe author's depiction of Solar-Thermal trough as the example to illustrate the technology is a bit dated and therefore misleading about cost. The author isn't aware of the Solar-Thermal product of Ausra (http://www.ausra.com/). Ausra claims to be able produce power competitive with fossil fuel based generation - roughly in the 10 cents per kilowatt hour range.
Reply | Report Abuse | Link to thisRidiculously.
Reply | Report Abuse | Link to thisSimilar, in USA to write are able, and to read - no.
I have informed, that there is a technology of transformation of heat of an environment in a constant current.
Has informed, that at identical cost with solar photovoltaics the panel nyquistors gives back in 300 times more to electrical energy.
I informed about 1.2 cents per kilowatt-hour.
To read nobody is able!
Our actor of a colloquial genre Zadornov was right, when spoke, that in staffs(states) the original people and logic at them original live.
I found Matthew Walds roundup on renewable energy alternatives very helpful in developing a perspective on the progress being made in each category of generation and energy buffering. We appear to have more than sufficient tools to completely replace fossil fuels and excessive CO generation; it is simply a matter of economics and refinement.
Reply | Report Abuse | Link to thisHowever I found the pricing information within the article confusing and leaving several questions unanswered. For example: the article prices Solar Photovoltaic at 46.9 70.5 cents/kWh. That does not seem to sufficiently account for the time variable; is that price for a panel in place for a single year, or for a 25 year life cycle? Does it include operating and maintenance costs? SPV is relatively passive when compared to the operating and mechanical maintenance costs of most other renewables. It would be helpful if the author had provided a price to build, in $ per effective kW, and a price to operate, in $/kWh for each of the alternatives, along with similar numbers for the currently used fossil fuel plants.
George Sitts
Oakhurst. CA
Matthew Wald’s roundup on renewable energy alternatives helped develop a perspective on the progress being made in each of those categories of generation and energy buffering. We seem to have more than sufficient tools to completely replace fossil fuels and excessive CO generation; it is simply a matter of economics and refinement.
Reply | Report Abuse | Link to thisHowever I found the pricing information within the article confusing and leaving several questions unanswered. For example: the article prices Solar Photovoltaic at “46.9 – 70.5 cents/kWh.” That does not seem to sufficiently account for the time variable; is that price for a panel in place for a single year, or for a 25 year life cycle? Does it include operating and maintenance costs? SPV is relatively passive when compared to the operating and mechanical maintenance costs of most other renewables. It would be much more enlightening if the author had provided a price to build, in $ per effective kW, and a price to operate, in $/kWh for each of the alternatives, along with similar numbers for the currently used fossil fuel plants.
-George Sitts
Oakhurst. CA
Your article A Concise Guide to Renewable Power was quite disappointing. Although the concise part was very well done, several major items were ignored:
Reply | Report Abuse | Link to this1. The perspective was strictly from a large centralized generation/transmission source. Distributed renewable generation, specifically at homes and small businesses, could offset 20% or so of the total consumption, without requiring any new transmission or distribution lines. There are no real technical or economic obstacles, only the aversion to change from the large centralized generators/transmitters and the lack of standards (adequate codes and regulations such as the NEC, but no standards, i.e., like those used in the Integrated Circuit or the IBM-clone PC industries to promote acceptance and growth).
2. Solar heating of domestic hot water alone could reduce non-renewable energy consumption by 10%. There is no technical nor economic reason why virtually all homes and small apartment buildings should not install solar domestic hot water heating. Again, there is the lack of standards (there are adequate building codes and regulations), but that problem could be readily cured.
3. Solar cooling and space heating is viable for much of the country. While not the economic no-brainer that solar domestic hot water heating is, the systems are economically viable and could reduce non-renewable energy consumption by 5% or more.
4. My initial photovoltaic system installed 12 years ago, using an abbreviated lifetime estimate, produces electricity that cost ~ $0.33/kWh, which is significantly below what the article quoted. While I agree that a realistic current cost for small systems of $0.15 to $0.25 is still higher than available grid electricity, the option to use, especially for residential applications, still makes some economic sense, when considering the long term. I am retired, but made the investment while working, that investment makes even more sense now than when I retired 10 years ago.
5. While eventually, the problems of over-population, especially in cities, will dominate the generation, transmission, and distribution issues, an evolution (rather than a revolution) to a balance of large centralized and small distributed generating facilities would benefit all. Small distributed renewable energy systems are not a stand-alone complete solution, but when integrated with large centralized generators (renewable and nonrenewable), provide a much more sensible (economic) solution to the current and future investment and control problems associated with usable energy generation, transmission, and distribution.
Very few people seem to be aware of the so-called 'Trombe Wall' system of solar heating for homes. Trombe was a French scientist who painted the south facing wall of his house black. This was then covered with panes of glass. The wall absorbed the heat of the sun, which heated the sandwiched air which rose and was ventillated around the house. Simple, cheap and very effective! In summer, vents allowed the heated air to simply escape.
Reply | Report Abuse | Link to thisWhen writers quote prices for distant, centralized power generation vs. power generated at the point of consumption, it is never made clear if transmission & distribution losses are accounted for it the cost/kWh given. For example: solar at a (theoretical) $.22/kWh might appear more competitive against an (avg.) $.11/kWh coal if there are 50% transmission & distribution losses. As a consumer I need to know "total life-cycle" cost when considering options. Initial construction, maintenance, environmental, govt. subsidy, etc.
Reply | Report Abuse | Link to thisNice idea, but imagine trying to retrofit millions of homes and businesses with heat pumps. The typical home doesn't have enough yard space to allow a backhoe or drilling equipment to either make a vertical or horizontal ditch or hole to do this.
Reply | Report Abuse | Link to thisRetrofitting is NOT an option for the VAST MAJORITY of homes. It just will NOT happen no matter whether the gov't mandated it or not, and no matter whether there were unlimited funds to do so.
The answer is to reduce usage for existing homes and insulate them. Going FORWARD with new construction, heat pumps could be a great solution for energy-strapped locales.
Thousands of commercial installations including offices and schools have been storing ice as thermal energy for daytime air-conditioning loads. One of the largest privately owned companies is in NJ- www.Calmac.com
Reply | Report Abuse | Link to thisThere is a kind of renewed power about which in USA nobody knows.
Reply | Report Abuse | Link to this1. Name: " Isothermal transformation of heat to mechanical job or electrical current (heatmechanic or heatvoltaic) ".
2. Code: "- !" (energy obtain surround - energy taken away at a vicinity). The abbreviation of the name of new power coincides with a name ->A - ancient Greek goddess of morning - ->A (Eos).
3. Condition of development:
3.1. The demonstration of a working breadboard model proves a basic opportunity of the project - !.
3.2. By numerical accounts on standard techniques of account (through entropy and internal energy of substance of a working body) is shown:
3.2.1. Specific cost of converters in serial manufacture - no more � 30 kW.
3.2.2. Specific weight of isothermal converters - no more than 0.6 kg / kW.
3.2.3. Rated power of converters =>@<8@C5BAO at temperature ?>42>40 of heat a minus of 80 degrees Celsius.
Nice article. There is a new world emerging web range before our eyes. This is a global energy network and, like the Internet would change our culture, society and the way we operate. More importantly, it will change the way we use, transform and exchange energy. Enough solar energy falls on the surface every 40 minutes to meet 100 percent of global energy needs for one year. There is no energy problem, there is a problem of energy supply - and this new solution is a new World Wide Web of electricity. Renewable Energy Sources : http://www.globalwarming360.net/
Reply | Report Abuse | Link to thisRenewable energy can and should be promoted by taxation. The health issues of air pollution alone add up to billions of health care dollars that could be saved using cleaner technology.
Reply | Report Abuse | Link to thisThe key would be to implement such a tax gradually - say over the course of 20 years. During that time, manufacturers and consumers would see the vision of more efficient energy use coming, and both would be able to adjust over product lifetimes to more efficient products. For gasoline, as an example, a tax increase of just ten cents per gallon per year would yield an added tax of $2/gallon in 20 years - probably enough to improve fuel economy significantly, but not disruptive to the general population.
The problem is not taxation. The problem is developing a vision of energy sustainability and moving in a constant and purposeful way toward that goal.