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Posts Tagged ‘power’

Combined-Source Energy Farms

March 10, 2010 1 comment

We see more wind and solar farms popping up every day. What we don’t see (or at least I haven’t seen) are the two being built in the same place. Think about it: the only times that solar panels don’t generate electricity are at night, and when it’s cloudy. Generally it gets cloudy as a result of weather systems, which usually cause it to be windy. So why is it that we see wind farms and solar farms as totally separate facilities?

If the goal of building a renewable generation facility is to power a certain area of the energy grid, it only makes sense to utilize every source that we can. The biggest problem with renewable energy plants is their downtime. The sun only shines, and the wind only blows, at certain times. Building solar collectors and wind farms together could greatly reduce downtime of the facility by taking advantage of the weather, and prominent energy source at a given time. A solar farm that generally loses 30% of it’s uptime due to weather could greatly benefit from a wind farm that would make use of most, if not all, of that downtime by taking advantage of the weather systems passing through. With this method the capacity factor of renewable energy generation facilities could be increased to compete with current coal, oil, and nuclear plants.

The amount of generation capacity per energy source could be adjusted to suit a given area. For example, a wind farm located in a natural air stream would not see much necessity for incorporating a large solar collector, however a small one may be added simply to increase the efficiency and capacity factor of the overall facility. Likewise, a solar array in a naturally dry and sunny location may increase it’s capacity factor with a few wind turbines.

The biggest advantage of this setup, however, is that renewable energy generation facilities can be built in areas that do not favor one form over the other. Many towns and cities that do not have major wind currents, nor an exceptional amount of sun, can get reliable renewable energy from a plant that balances wind and solar sources. This now creates the opportunity for many cities and villages to generate their own renewable energy. Benefits could also be seen by building combined-cycle plants, generating both electricity for power and heat for the town or parts of the city.

There is a lot of energy out there just waiting to be harvested, we just have to build the facilities to use it. I think that all energy farms, being built for the sole purpose of powering a certain area, should take advantage of the different sources of energy available. What do you think?

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The Flaw With Fusion

Fusion target implosion on NOVA laser

Fusion power is currently the undisputed ideal form of energy production. It is similar to the current widespread nuclear fission power, but instead of using enriched radioactive fuel, it works by focusing intense energy on a single point, causing several atoms to fuse into a single, larger atom. This is the same kind of energy that powers the sun. The easiest fuels to use are the isotopes of hydrogen: deuterium (²H) and tritium (³H), because they react at the lowest temperatures.

But you didn’t come here for a chemistry lesson. The fact of the matter is that fusion power has been marketed to the public as being able to use water as fuel and produce helium as a byproduct, which is true. But even though this form of production is incredibly efficient, we are still turning water into helium. I know what you’re saying, there’s a LOT of water on this planet, right? How much can we afford to lose? There is only so much water on this planet at one time, and we will never get that water back unless we invest the energy to turn the helium back into water.

These power plants are said to only need to consume one liter of water to produce the power we get from 500 liters of petroleum. But how much water do you think it will take to power the whole planet? In 2008, total worldwide energy consumption occurred at a rate of roughly 15 terawatts (source). If I did my math right, it would take 22,000 lbs. of water to power the Earth for one day on fusion power, that’s over 4 thousand tons per year!

That may not be very much water in relation to the amount on the planet right now, but we’re talking about permanently upsetting the balance. Once fusion power becomes economically and technologically feasible, and energy becomes more cheap and abundant, we will most likely start using more of it. That will result in a decrease in the amount of water in our ecosystem and an increase in the amount of helium.

That being said, fusion power will most likely be able to safely power our planet for at least a few thousand years, probably long enough to find a more reliable energy source, or a more abundant source of nuclear fuel. But people need to know what fusion power is all about before endorsing it. It’s not an end-all solution to the world’s energy problems, nor is it completely safe. It’s not even considered a renewable energy. I think that when fusion power becomes a reality, it should only be used to supplement renewable energy sources, not as the primary energy source. When you break it all down, the only true sources of renewable energy that we know of right now come from the heat of the Earth, or from the sun.

Clean Energy Finally Gaining Steam

March 5, 2010 7 comments

Finally, somebody said what I’ve been waiting to hear, “… no member of the public has ever been injured by a nuclear power plant in the United States, nor has any nuclear worker died of a radiation-related incident…”, a statement made by Patrick Moore today in the LA Times. This is exactly what I’ve been talking about. People got all hyped up with the accident at Chernobyl (which happened under extremely rare circumstances, by the way) and decided never again to trust nuclear power. There is your proof that nuclear power is clean and safe, despite what people want to think about it. How many people have been killed in coal mines, or in natural gas or oil rig explosions?

We do have renewable energy sources right now: wind, solar, tidal, geothermal, etc. But they are not yet efficient or widespread enough that they can sustain our energy economy. Nuclear power is our next step to clean energy. People need to get over their preconceptions and accept that there is nothing wrong with nuclear power, it has been around for over 50 years now and the technology is well developed and widespread. They want to get rid of greenhouse gases, why not get rid of the big coal powerplants?

The extra money that we would save by getting rid of coal power could be put into research and development of nuclear fuel reprocessing technologies. I think that the big thing that people worry about is spent reactor fuel. Obviously, more reactors would mean more spent fuel. But it would also mean more funding for reprocessing research and storage facilities.

I believe that we are less than 50 years away from seeing reliable fusion power become a reality. When it does, we won’t need traditional nuclear fission reactors anymore, so you can do away with that waste. There is enough nuclear fuel on this planet to last us a long time, much longer than fossil fuels, which are running out fast. Our energy economy needs an overhaul, we’re not in the 1900’s anymore. Maybe coal and oil power was a bright future back then, but now, over 100 years down the road, supplies are running out and we’re seeing the repercussions of living this way. We can’t stay stuck in our ways just because we don’t want to change. The good times with fossil fuels are a thing of the past, now it’s time for us to grow up and move on to bigger and better things.

Nuclear Waste May End Up In Our Backyards

The Energy Department filed to withdraw an application for a nuclear waste repository at Yucca Mountain Wednesday in an attempt to reverse a policy set and invested in by the Bush administration (source: Wall Street Journal). A new panel was created by the Energy Department and the Obama administration hopes to develop a new plan for disposal of nuclear waste.

The Yucca Mountain facility, located in the Nellis Military Operations Area in Nevada, was intended to be the first national repository for spent nuclear waste, a one-of-a-kind facility designed for this sole purpose. The government has already rewarded at least $2.5 billion in contracts to maintain the facility.

If the Obama administration wants to go all-out on renewable energy sources, then by all means, let them. But taking away the infrastructure for our existing energy generation facilities is not the way to go about doing it. The fact of the matter is that we rely heavily on nuclear power at this point in time. As of November 2009, 20.2 percent of energy produced in the US was from Nuclear (source: USEIA), a 2.5 percent increase from 2008. Despite all of the skepticism and hype about nuclear energy, it is one of the cleanest non-renewable energy sources out there. There have been far fewer incidents and deaths related to nuclear energy in the US than there have with coal power plants. Coal power still accounts for almost 45 percent of our annual electricity production, would we rather have coal power or nuclear? I, for one, would rather live next-door to a nuclear reactor than a coal power plant. We can’t just jump right in to an absolute renewable energy economy and expect it to work, we first need to phase out the other forms of production: coal first, then natural gas and oil, then nuclear.

The nuclear reactors aren’t going to go away. It makes more sense for the waste from them to be stored in a dedicated facility than to rely on individual companies to do it their own way, because you know that they will cut corners. If the Obama administration has a better idea, they’d better get going, because it’s just a matter of time before there will be an accident involving spent nuclear fuel that was not disposed of properly.

Home Bi-generation

Generator

It is a known fact that the modern internal combustion engines in automobiles have a fuel-to-wheels efficiency of only about 25%, maybe a little more in the newer hybrid vehicles. In fact, if you are interested in the physics of this I found this article very interesting. The main opponent here is friction. It’s been proven that most of the energy that is converted from fuel in an internal combustion engine ends up as unusable heat. Ever wondered why cars and trucks need that big ol’ radiator in the front? It has to be large enough to remove 600 Horsepower worth of heat from your 200 Horsepower engine, because that is about how much energy is going to be lost as heat at maximum power. Obviously the modern internal combustion engine, though reliable and popular, is not very efficient at producing tractive power.

If our homes need both heat and power, why don’t we just generate them both ourselves.

If we turn the numbers around here, we realize that the internal combustion engine is actually quite efficient at producing heat. If you live in an area the gets cold winters, you might know first hand that automotive engines can produce a good amount of excess heat. I’ve had the window down in my little car in the middle of winter and been perfectly comfortable (even a little warm), while the engine coolant temperature remains unaffected, as if boasting that I can’t cool it down. See where I’m going with this?

If our homes need both heat and power, why don’t we just generate them both ourselves. We have gas heaters with the potential to make electricity, and we have gas generators that make excess heat. A single generator in every home could be used for heat, energy, and other things. The real question here is: would this be more expensive? I guess the answer depends on what kind of device we use. I wouldn’t use an internal combustion engine, they are too loud, inefficient, and not really designed for that length of service. Gas turbines are reliable and great for constant-speed, constant-load applications, but they too are loud and somewhat inefficient, especially on a smaller scale. I think for this one we should go with the proven prime-mover of our energy market: steam. A steam boiler can provide electrical power through a turbine and generator without too much noise or excess waste. The turbine could also provide rotary power for other devices like air conditioning and water pumping. Heat could be distributed through steam pipes and convectors, transferred to a hydronic heating system, or exchanged through a forced air radiator. A loop could even be provided in the system to heat water. Most homes already have a furnace of some sort installed in them, I see no reason that a generator couldn’t take the place of it.

But what about the efficiency of this whole scheme? Well, if we think about the efficiency of the power generated by a coal-fired power plant, which is only about 33% as noted here, it’s not much better than an automotive engine, not to mention energy losses in transmission and various other parasitic losses. With heating boilers becoming increasingly more efficient, up around 95%, I see no reason that a bi-generation system could not be even more efficient while providing cheaper power, heat, and other utilities. This is definitely not a solution to reduce the consumption of fossil fuels, but there is huge potential here for individual power. Also, the existing power transmission grid could be used as a buffer, feeding into the grid when generating, and consuming from the grid when not.

Maybe this is not something that every house and every building in the world should be doing, but for places that are far from other utilities, like cabins, mountainous areas, and deserts, there is some serious potential. Perhaps the urban areas should get their heat and power from a power station, and smaller suburban and country homes should make their own. Just my thoughts, what do you think?


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