Wisconsin Energy

Power Generation

Buildings need to be build as efficiently as possible. And there are power stations that provide the energy used in buildings. In order to live sustainably both parts of the equation need to be improved. We only want to give some overview of the generation types and their environmental issues. As with everything, there is no magic bullet and magic technology that can resolve all our problems.

Coal Nuclear Natural Gas Biomass Hydropower Wind Solar Smart Grid

Power Plant and Fuel Types

The following summarizes the power plant and fuel options available in Wisconsin. Power plants have a life of up to 50 years and it is impossible to predict the circumstances that a power plant owner has to face at the end of the life of the plant.

Different fuel prices are interdependent and price increases force the market to use alternative fuel, driving up cost of other fuel source. One critical issue is the depletion of oil. Oil is not used much for electricity production in Wisconsin (mostly Hawaii and Alaska). But as a fuel that mostly is imported from overseas and most likely will be short in supply within the next decade (even if later than that, it will be short in supply before cal, gas and Uranium) It causes a chain reaction triggering shortages and price increases of other fuels. Oil shortages and high oil prices will cause:

Increased tar sand extraction (i.e. Alberta Region in Canada) and hence limit Natural gas supply; this in turn can cause more coal gasification, limiting coal supply
Coal liquefaction (as done in South Africa, and Germany in WWII) and hence limit coal supply
Use of electric vehicles and hence cause more power plant usage of other fuels
Use of liquefied natural gas for heavy vehicles and hence limit natural gas supply

These are just some examples and it is not possible to predict market prices. There also is some interaction between fuel price and effort made to explore and extract fuel, interaction between energy price and energy conservation efforts and economical development. Analyzing and predicting scenarios easily is used for political reasons and not part of this paper.

Public discussion about the ideal power source are highly ideological and often biased. Most people discussing in a white/black scheme do not have the technical knowledge to realize that each of the power sources has major disadvantages and that a fuel mix will be needed.

Ironically “environmentalists” argue against certain technologies without much knowledge and without focusing on the big picture. There is no technology without any negative impact on the environment. The only 100% positive technology would be for mankind to cease existence. Since this is not the goal, the technology-mix with the least negative impact needs to be found.

Coal Power Plants:

The dominant power source depends on imported coal. Coal is said to be available in the US for many decades. The US has lots of coal and use of coal won’t add to the trade deficit. Although, domestic use will limit ability to export coal. Coal Power plants are known, readily available and produce reliably power. The technology is known and has little risk. The fuel (currently) is cheap. Plants can be in large size (over 1000 MW) and in smaller sizes (tens of MW, often in combination with usage of waste heat). Coal power plants mostly operate as base power plants. However, they also can be used for (limited) peak power. There are many newer coal power plants, ensuring a long operational life for many years to come (unlike nuclear, s. below) Challenges coal that power plants face are:

Not much peaking capacity / mostly base load only
CO2 emission is very high and due to CO2 emission cost plants can become a liability. Any Carbon sequestration technologies have not been tested yet and will decrease efficiency significantly (requiring larger plants and burning of much more coal) and will increase operating cost significantly. It is totally unproven technology with no evidence of actually trapping CO2 for a long time. Large scale operation of equipment that separates CO2 from the exhaust stream, liquefies it and stores it underground is technologically challenging or may even be impossible.
Pollution is high, cleaning of coal power plants is both costly in capital, and increases operating cost due to less efficiency (this also increases CO2 emission) and operating cost. Even with pollution control emissions are worse than natural gas plants. Many deceases (asthma, mercury in lakes etc.) are related to coal.
Not accepted by “neighbors”. No one wants a new coal plant nearby. Many advocates don’t want them at all due to air pollution and CO2 issues.
Fuel is imported to Wisconsin. Extracting money from Wisconsin. Availability of barges, trains and other transportation is limited. Investments in infrastructure would be needed to increase usage of coal.
Coal mining mostly is done by strip or open pit mining; often leaving the ground as a lunar surface. Land use, wildlife, water sheds and other environmental issues exist. Often clean up is paid by the tax payer. This adds to the high social cost.
Coal as fuel might be depleted sooner and get more expensive if it is used as substituted for other fuels. Many countries of the world (i.e. China) increase coal production to the point that they switch from being coal exporting countries to be coal importing countries. This likely increases coal prices in the US since mining companies could sell US coal to markets with higher demand. Any import will add to the trade deficit.
Coal quality may be diminishing as high-quality coal had been mined first. This making air pollution control, mining, transportation and combustion more expensive.

Nuclear Power Plants:

The second largest source of electricity produces almost no emissions including CO2. The fuel is cheap and (relatively) easy to transport. The operation of the plants is steady and for baseload. Many advocates praise nuclear energy for those advantages and actively want to promote it. Challenges that nuclear power plants face are:

No peaking capacity / pure base load plant
Storage of nuclear waste is uncertain and likely expensive. Decommissioning of old plants, waste storage (often needed for thousands of years) becomes a liability for future generations. In modern times there are additional safety concerns that terrorists or enemy nations could get hold of nuclear material. Obviously more nuclear waste increases that likelihood.
Although the operation in the western World has been relatively safe, there have been incidents. Even if accidents are less likely they are disastrous and in their magnitude without comparison to any type of accident in any other facility. The nuclear industry has relatively little insurance coverage for accidents and any additional cost is to be paid by the tax payer. Another risk that was not considered when plants were built is that nuclear power plants and facilities of the nuclear fuel cycle could be targets of terrorist attacks. Older plants have no protection against hits by airplanes. Newer plants have protection against hits by smaller airplanes, but not commercial airliners.
There is some statistical evidence of higher leukemia rates near nuclear power plants. There does not seem to be much scientific evidence and impacts seem to be less evident than the coal “power plant – asthma” correlation, though.
Due to regulations construction and operation (mandatory safety retrofits etc.) is expensive. (low energy prices are achieved by old nuclear power plants that are written off). In addition the industry does not have any recent experience in building nuclear power plants in the western world with western regulations. All recent power plants have been built in countries with lax regulations only. Building a nuclear power plant would be an Endeavour for a utility that would not have fixed price tag, nor set completion date. Most equipment has to be specially designed. In addition most plants are many decades old, nearing the end of their life within the next decade. Construction time is estimated to be over 10 years.
There is a supposed shortage of nuclear engineers capable of designing and operating nuclear power plants. Due to the risks, that shortage can be a deal breaker.
Uranium supply is estimated to last for 60 more years at current consumption. This time may be shorter with other countries building up nuclear power plants. In addition, the US only has access to 7% of the worlds Uranium (but uses 25% of world energy). Fast Breeders are said to extend the usable life of nuclear fuel. However, all western nations have ended or are ending commercial operation of such breeders due to financial, technical and environmental concerns. Any imports will add to the trade deficit.
Planning and construction of a plant will meet heavy resistance by the population nearby.

Natural Gas Plants:

Natural gas plants carry much of the peaking load and are the most accepted and environmentally friendly fossil fuel plants. In combined cycle and waste heat usage operation they are very efficient and emit much less CO2 and other pollutants than coal power plants. Drilling for natural gas has very little impact on the area, as opposed to coal mining for example. Due to their political acceptance and ability to be built in small units and no need for coal trains they can be located near cities, which reduced load on the transmission grid and enables waste heat usage. There are even residential size units that produce electricity and heat. It may be possible in a smart grid to store that heat and produce electricity when needed at peak demand. Challenges that natural gas power plants face are:

The fuel is more expensive than coal or nuclear fuel, making them less economical for base load operation.
The fuel supply is assumed to be in shorter supply in the foreseeable future. This can be overcome by importing LNG (liquefied natural gas) and usage of alternate natural gas sources. Those sources include natural gas trapped in rocks etc. LNG mostly is sourced from unstable regions (Middle East) and requires expensive infrastructure and very much energy compared to US pipeline transport. Use of the alternate sources is not being done in large scale yet and only possible at relatively high natural gas prices. There is not a real shortage of natural gas, but there will be a shortage of cheap natural gas. Any imports will add to the trade deficit.
Leaks in the fuel supply release methane, which is said to have 23 times the greenhouse gas capacity of CO2.

Biomass Plants:

Solid Biomass Plants often are part of a coal plant where a fraction of the coal is replaced by biomass. Also biomass-only plants are in use. The fuel can be grown in Wisconsin, supporting the local economy and reduces CO2 emission since the growing biomass absorbs the amount of CO2 that is released at combustion (Coal, Natural gas and Oil is “old” biomass and not “grown” anymore, therefore that CO2 stays in the atmosphere). Pollution likely is less dirty than coal since biomass does not contain sulfur. Some biomass is converted to methane or alcohol in fermentation processes. This occurs naturally in landfill, for example, and this gaseous and liquid fuel can be used for combustion to substitute fossil fuel the same way solid biomass is used. Especially landfill gas and manure gas usage is of advantage since not much effort has to be made to produce those gases and the combustion of such protects the climate since it prevents release of methane to the atmosphere. Biomass plants have a relatively stable fuel supply and can be used for some base load and some peak load production. Politically, biomass usage is in favor with very many parties. Challenges that biomass power plants face are:

Fuel has lower energy density than fossil fuel and in case of grown crops it is harvested seasonally. In order to use biomass all year around storage is an issue, especially since it needs to be dried and biodegrades
Drying of solid biomass requires energy, and the lower combustion temperatures may reduce the efficiency of the power plant cycle and de-rate the power plant. Fuel quality (energy content, moisture content) can vary, making a stable usage difficult. To overcome this, a 20%-40% biomass usage in 4 coal plants might be better than 100% biofuel usage in one plant.
Transportation needs are increased as well as onsite storage. As seen for the proposed charter street plant, wider railway corridors, right-of-ways and aesthetic obstacles due to silos can be an issue near cities. Requiring 5-6 times the number of train cars can exceed the ability of the transportation system and have other negative impacts near cities (noise, traffic jam etc.)
Air Pollution Reduction and combustion equipment may need to be specifically designed and/or altered to accommodate a fuel source other than coal. This however is only a relatively modest expense.
The fuel is grown with much land use, requires energy and the use of fertilizers (require natural gas), herbicides, and pesticides. Many of the crops require tremendous amounts of water, which adds to the water shortage problems in most of the US. In the (relatively moist) Madison area the water table drops by 1-2 feet annually due to municipal usage. Similar drops are prevailing in other areas that pump water from the ground.
There is a limit to how much biofuel can be grown in a year and more extensive agriculture is energy-intensive and might exhaust soils faster, making biofuel not renewable. In addition biofuel usage will require usage of new farmland or farmland that was idle. This may require cutting down forests, drying wetlands or using prairie land. This all will release large amounts of greenhouse gas and hurts wildlife.
Usage of biofuel increases food prices, which has large economical effects on poorer parts of the population or poorer countries.
Use of landfill gas or sewage gas itself has positive impacts. However, it is based and depends on a wasteful life style in the first place. If resources would be used better (which will have to be done), there would be less of such resource to drain from. In the end that gas only is a small fraction of the energy that was in the original product.

Hydropower:

Hydropower has been used reliably and in large scale to produce electricity way before fossil fuel was used. It provides large and stable amounts of energy at relatively low cost. There is virtually no air pollution or CO2 production. Lakes can be used for recreation. It has some capability to throttle its output to provide peak and base load. Hydropower is a renewable energy source that is price-competitive with fossil fuel plants. As an energy source that does not require import of fuel, it is good for the trade balance. Challenges that biomass power plants face are:

Especially in Wisconsin, there is not much potential for hydropower left. This only leaves the option of importing hydro-power, which in turn would require transmission lines, which add cost, waste some energy, and it is doubtful that any CO2 would really be saved, since the hydropower would be used somewhere else anyway. It is unlikely much new hydropower would be built because of purchases from Wisconsin.
Creating artificial lakes can be unacceptable and impossible due to space or environmental issues. Very large lakes can change the local climate, cause socio-economic problems (as the Chinese Three Gorges dam, that displaced 2 million people and altered local climate with is large water body and caused other problems affecting the river). Wildlife in the river can be extinct if no measures are taken. The impact on wildlife is severe, although possibly not as severe a as coal mining, uranium mining etc.
In order to produce much power a high elevation difference is needed, limiting hydro-dams to mountainous areas. Hydropower using the kinetic energy of water only are limited in power outpus. Although, they can be beneficial on a small scale.
Seasonal availability of water and droughts can be a problem. Especially when summer need for electricity is the highest this is a problem, as droughts tend to happen when it is warm. All thermal power plants have problems with water shortage as they require cooling, but hydropower obviously is affected most.
Sediments accumulate in and need to be dug out. Those sediments also are suspected to ferment and release significant amounts of methane and CO2, which are greenhouse gases. However, it is doubtful those greenhouse gases are anywhere near as dangerous as the CO2 displaced if a coal power plant was used instead. But they needed to be accounted for in a greenhouse gas balance. Certainly more research needs to be done to accurately judge this technology.

Wind Power:

Wind Power has been used for many centuries and is a renewable energy source that is economical compared to fossil fuel (this can be argued, but depending on location and market it often is competitive) and is deployed in very large scale installations. Older plants were in the sub-100 kW range, later in sub 1 MW classes and current turbines are in 2.5 MW size. This drove done the price per kWh significantly and enables large scale usage. May installations happen in agricultural areas, not requiring much additional space as the land around them still is usable. There have been off-shore projects that have the potential to be even more economical and take advantage of more steady winds, increasing the capacity factor. There are experiments and research for high-altitude wind that promises lower energy prices and much higher capacity factors. Overall, wind power has a good potential to play a significant role in the future energy supply. Challenges that wind power plants face are:

Wind resources are unevenly distributed and can vary locally. Typically wide open areas without buildings or forests are required. Wisconsin has far less wind resource than other states, making investments in Iowa, for example, and importing power from there, more economical. Since power output depends on the 3rd order of wind speed, half the wind speed can mean only one 9th of power output.
Wind Power output often is highest in winter and at night time (partially due to the higher air density at lower temperatures), at the time the least electricity is needed.
There is some resistance against building wind turbines near developed areas. This is not much more resistance as resistance against anything else that could be built near developed areas, though.
Some environmentalists are concerned with impact on wildlife, especially birds getting disoriented and hit by wings. This is a minor issue only, though. Studies in Germany (13% of electricity produced by wind) and other countries with high usage of wind (i.e. Denmark) show that “Vogelschlag” is not important, especially compared to the number of birds killed that hit illuminated high-rise buildings at night time, fly into airplanes or are killed by mining activities, or agriculture, or by cats. Although compared to any other electricity production bird killing is insignificant, lobbying groups use this as an argument to prevent wind power developments.
Wind electricity is not dispatchable, the grid has to use it whenever the wind blows. This causes concern for the stability of the grid and may require storage and/or additional peak-powering plants. This is not as big of a problem as utilities make it sound since the wind-power fraction is relatively small yet and other countries with higher wind power usage are able to deal with the problem.

Solar Energy:

Solar energy has made much progress and is politically in favor with many parties. The two technologies (Photo Voltaik and Solar Thermal) can be used in relatively large scale (although currently much smaller than fossil fuel plants) and production occurs during daytime, coinciding with the highest electricity usage. PV can take advantage of direct and diffuse solar radiation and does not require water for cooling, nor requires much effort for operation or maintenance (solar thermal plants require operation of a Rankine or other heat cycle, which is complicated to operate). Therefore PV can be used in very small scale. PV is the almost only power generation that even homeowners can install on their house. There is some advantage for grid operation to have the power plant right where the energy is used. Future projections assume decreasing prices for PV panels. Solar resources in a region are very similar at many locations, making production numbers more predictable than wind power. Solar thermal plants have the potential to store heat energy, enabling some dispatchability. There is very little impact on the environment and not greenhouse gas and pollution emission. Solar energy is the most accepted technology and price is the only obstacle for acceptance. Challenges that solar power plants face are:

Non-dispatchable, the grid has to use the Energy whenever the sun shines.
Only areas with high percentage of direct radiation can take advantage of solar thermal plants that require focusing of solar rays. Wisconsin has a large fraction of diffuse radiation. Although PV systems work on cloudy days as well, the production numbers are significantly lower.
The average peak production occurs at solar-noon, which does not coincide with the peak energy usage, which may be at 15:00 – 17:00. However, solar energy systems still are more likely to supply power at peak air conditioning use times than wind power plants.
Currently the installation price is very high. There are projections to allow price-parity with fossil fuel within the next decade. This obviously depends on regulations and market forces too and still does not solve the dispatchability problem.
There is much space use associated and the space underneath arrays cannot be used for agriculture (as it can with wind installations). However, all the unsued space on roofs can be used relatively easily.

Smart Grid Technology and Energy Conservation:

Although the grid does not produce any power, it plays a large role in how efficient each technology can be used. Any large ratio between average use and peak use is of disadvantage as it requires more capital investment in grid and power plants. A future “smart grid” could shift demand to off-times, use widely spread dispatch able units to produce temporary peak electricity and can save energy by reducing transmission losses. Technologies that help the grid and the power plants are ice or other thermal storages to use off-time electricity to provide space cooling or heating. Long distance DC-transmission can reduce transmission losses, remote load–shedding can temporarily disable certain power users (i.e. AC, heaters) to avoid temporary peaks, and can transport power from non-dispatchable plants to areas with a need for electricity. This all will enable the full usage of each power plant type, and can have plants be operating more efficiently. Part of the grid would be energy storages. Those storages could be hydro dams pumping water up to a reservoir at off-time, compressed air, or batteries for small scale. Another advantage of the smart grid is increases stability and reliability.

The most economical power plant is the one that does not need to be built. Energy conservation both reducing demand and on-time of equipment is very cost competitive. Depending on the technology currently used, the investment can be paid back in very few years with almost no negative impact on the environment. It is said that every dollar spend on energy conservation has the same effect as every 5 $ spent on renewable energy, which also may have some negative environmental impacts. Energy conservation measures are very mature and readily available and are being used on large scale in commercial and industrial applications. Many of the technologies can reduce electricity demand by 30-% - 50% (lighting, Variable speed Drive) and reduce other operating cost (maintenance) and improve the comfort of users. Especially with increasing energy prices, energy conservation measures become more economical and will play a big part in the future “electricity generation”.

Challenges that smart grid and energy conservation face are:

Renewing the grid will be expensive and may require new transmission lines that face opposition. On the other hand, the expense will be offset by investments that need to be done anyway to maintain and grow the existing grid to accommodate projected energy demand. With energy conservation and peak-shifting measures the total capacity could even be less than the BAU (business as usual) scenario.
Energy conservation has its limits and may require change of habits. While there may be engineering solutions to save even more energy, changing habits can be more difficult. However, if the price-pressure is high enough habits may change.
Large investments need to be made to retrofit existing building and industrial facility stock. Much of it was designed and built in times of cheap energy and significant changes may be impossible or expensive while maintaining the original function of the equipment or facility. However, the energy savings typically offset investments within a few years. Energy prices (and possibly regulations) can make it mandatory to upgrade facilities and buildings in order to stay competitive.

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