Sunday, April 4, 2010

Will Reducing the Cost of Solar Panels Make Solar Competitive With Fossil and Nuclear Power Generation?

Plastics could slash the cost of solar panels dramatically, says Dr. Yueh-Lin Loo, an Associate Professor of Chemical Engineering at Princeton University. Dr. Loo and her team have developed a new technique for producing electricity-conducting plastics that could replace the extremely rare and costly Indium Tin Oxide that is currently used in solar panels, to conduct electricity.

"Conductive polymers [plastics] have been around for a long time, but processing them to make something useful degraded their ability to conduct electricity," said Yueh-Lin Loo, an associate professor of chemical engineering, who led the Princeton team. "We have figured out how to avoid this trade-off. We can shape the plastics into a useful form while maintaining high conductivity."

 There is no question that this development could make solar power much more viable and economical, and the best benefit of all is that it could make production of solar panels possible without the use of a rare and expensive material  But will it make it competitive with the highly concentrated energy available only from fossil fuels and nuclear?

That's doubtful, because the improvement in conductivity and efficiency, even by a major increment, will not solve the major problem with solar, which is its dependence on diffuse and intermittent energy. Intermittent energy is not only unreliable in itself, but the major limitation is in the transmission of power generated from a large number of small sources that generate intermittently.Stoneleigh, a major contributor to The Oil Drum and The Automatic Earth, describes the difficulty and vastly multiplied complexity of transmitting power generated in small amounts by large numbers of widely dispersed generators in her post on The Automatic Earth, Renewable Energy: Not in Your Lifetime:

As the power system was designed under a central station model to carry power in one direction only, with high voltage transmission and low voltage distribution, the modifications that would be required to enable two-way traffic, especially at the distribution level, are very substantial. Comprehensive monitoring and two-way communication would be required down to the distribution level, with central control (dispatchability, or at least the power to disconnect) of large numbers of very small generators.

The level of complexity would be vastly higher than the existing system, where there are relatively few generators to control in order to balance supply and demand in real time, and maintain system parameters such a frequency and voltage within acceptable limits.

The image above conveys by analogy the essence of power system frequency control - the easiest parameter to visualize. Frequency must be maintained at a set level by balancing supply and demand over the entire AC system.  There are 4 such systems in North America - the east, the west, Texas and Quebec - and each functions as a single giant machine. The trucks in the image are generators and the boulder they tow up the uneven hill represents variable load. The trucks must pull the boulder at an even speed despite the bumps. 

For a more accurate representation, one would actually need additional trucks, some moving at the same speed waiting to pick up a line if one should be dropped (spinning reserve) and others parked by the side of the hill (standing reserve). Some of the trucks would have to be able to start the boulder moving again from a standing start if it should stop for any reason (black-start). 

We are looking at a world where there would be many more trucks, but each would be much smaller, and some of them would only pull if the wind was blowing or the sun was shining. The difficulty of the task will increase exponentially, and frequency management is only one parameter that must be controlled.

The mismatch between renewable resource potential, load and grid capacity is considerable. Resource potential is often found in areas far from load, where the grid capacity is extremely limited. Developing this potential and attempting to transmit the resulting power with existing infrastructure to where it can be used would involve very high losses. Many rural areas are served by low voltage single phase lines, and the maximum generation size that can be connected under those circumstances is approximately 100kW. 

Even where three-phase lines exist, so that larger generators can be connected, carrying the power at low voltage is particularly inefficient, as low voltage means high current, and losses are proportional to the square of the current. Building high-voltage transmission lines to serve relatively small amounts of renewable energy would be an exceptionally expensive and difficult proposition, especially in a capital constrained future. 

Renewable energy generation far from load could amount to little more than a money generating scheme, as a premium rate will be paid from the public purse for the time being, but little of the power might reach anywhere it could actually be used.

Difficulties occur when generation proposed would amount to more than 50% of the minimum load on the feeder. At this threshold, special anti-islanding measures are required that add considerable cost to the grid connection. In North America, we have large geographical areas served by a network of long stringy feeders with very low load. Adding much of anything to this system will be very challenging.

 "Complexity", of course, means much more money and a complete overhaul and massive expansion of our electrical grid, far beyond what would be needed to supply three or four times as much power from conventional large power plants in order to power our transportation by electricity. It would mean, given our current population distribution, at least 8 times the grid capacity we now possess, not the three or four times current capacity that will be necessary to power all our transportation by electricity. Just meeting the needs of a comprehensive rail system is beyond the current capacity of our frayed grid.

The same limitations would apply to wind generation, another diffuse and intermittent source of energy. What this all means is that solar and wind, even were the costs of the components reduced substantially, will still be extremely expensive and unreliable means of generation, and will still rely upon fossil fuels for backup. They will vastly complicate the transmission requirements and in doing so, cause the costs to ramp up steeply.

And they ultimately rest on a fossil fuel platform, as James Howard Kunstler has pointed out, not only for backup, but for the ingredients in the manufacture and transportation of their components, as does the the nuclear power industry... and fossil fuels of all types- oil, coal, and gas- are depleting, and if we expect to retain any of the benefits of technology going forward, we are going to have to make the most efficient use of our remaining fossil fuel resources possible. In doing so, we will be up against frantic global competition for remaining reserves, escalating costs, and "receding horizons", for as the cost of fossil fuels escalate, so will the cost of building more power generation and upgrading the grid. It will take all the ingenuity of all of our best minds in combination with stringent conservation and the utmost economy in the management and deployment of our resources, to retain a minimal level of comfort and technological amenity in the decades ahead.

In such a context, should we pursue the least efficient forms of energy, those with the lowest EROEI, while spurning the most powerful and concentrated forms, namely nuclear, which is the most concentrated, powerful form of energy available? Can we afford to pursue wind and solar, while turning our backs on the most powerful technology ever devised, that could extend the fuel cycle for millinia while providing ample, cheap electricity for every community in the country? For, for every incremental improvement in "renewable", diffuse, intermittent forms of energy, there is a greater breakthrough in nuclear. We now have available to us many new and proven nuclear technologies that are not only extremely safe and leave almost no "waste", but which will reduce the costs of electricity to below that of coal and gas, two materials prone to rapid depletion.

Unfortunately, the decision as to which form of power generation we will commit investment rests in the hands of politicians and bureaucrats, not the "market", and several hundred million American lives depend upon those decisions. Let's hope our leaders choose wisely.


Thesolar said...

Solar panels being used for many years now, but cost of production to have own solar powered generator at your own home typically very high but the efficiency low, making them largely ineffective source of energy.

Make solar panels

The North Coast said...

Your statement seems verified by everything I've read.

I priced a solar array for my mother's house, which is partially shaded (a boon in St. Louis summers!), and came up with a figure of $30,000 for an array that would theoretically produce the power she draws from the grid now- about 200KwH a month. Even if the cost of electricity from the grid was to triple, which in her area would be about .24 a KwH, she couldn't begin to live out the cost of the system- and that's if it provided her with reliable 24/7 power, which of course it would not. Additionally, many of the components would deteriorate and need replacement long before they amortized themselves, and a system like this needs a inverter and batteries that have to be fussed with, and someone who knows how to deal with all of this.

A solar system capable of generating the same power as our 2GwH Braidwood nuclear plants would have something like a 15 sq mile footprint, and even then would not always work, requiring a fossil or nuclear backup.

To me, things like solar and wind mean using very dense and efficient sources of energy to produce very inefficient and diffuse, not to mention unreliable, energy. An instant massive net loss, worse than if we just continue to heedlessly burn fuel.