Power to the people

Distributed generation can strike a balance, change the paradigm

Published In: Intelligent Utility Magazine November/December 2011

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MOST OF THE WORLD CONSIDERS ELECTRICITY to be the answer to clean energy. The assumption is that all electricity can be created in a renewable fashion. This means a change in the way the industry operates.

For the last century, the power industry has been a load-serving industry-in short, running according to the maxim, "You turn on a switch and we will make more." In the future, that basic paradigm has to change if we want to support the maximum amount of renewable energy. The new paradigm has to be a supply-following industry, i.e., "If you make more, we will find a place to use it."

Even if we are successful at changing the industry, will consumers accept the new ways that power will need to be made in their backyards? Will they accept the infrastructure required to move the power from where it is made to where it needs to be used? These are the questions that industry and society will have to tackle and answer together.

Electricity demand vs. preserving nature
Some have no issues with windmills that are 300 feet tall being planted in close proximity to their communities and backyards. For others, any viewable windmills pose a problem, even if they are miles away. A more energy-efficient future may include such features as a horizon dominated by concentrating solar plants with acres of mirrors and towers that are each a hundred feet tall and are as bright as the sun if you look at them from the wrong angle; fields of photovoltaic panels (solar cells) that reflect the slightest light at night and can provide the same level of reflectivity as a well-polished car and that fill the fields that used to grow corn; dams and river turbines that generate power either around the clock or on demand and that may change the flow of the river water and store water for times when more power is needed.

How do we balance the demand for electricity with the idea that nature should be preserved? This is an issue that needs to be discussed and for which suitable answers need to be found. Today, much of the discussion is happening at the two extremes of public opinion and the people in the middle are sitting on the sidelines. The final decision on these issues may determine if we can even afford electricity in the future.

A measure of balance needs to be struck between the demand for energy and the ability to make it. It may end up that some regions of the country that reject new generation may end up paying much higher prices for energy that is imported from other regions and that power may become so scarce at times that people are without power for hours or even days at a time. California already experienced some of this with rolling blackouts in the last decade.

Distributed generation
Human-scale generation that is close to the locations where power is used has been a goal for the past 30 years. Distributed generation comes in many forms, ranging from diesel and gasoline generators to windmills and solar cells. Not all of this power is created equally and not all of it is especially well-liked by the public. A diesel generator humming away at three in the morning right after a hurricane is very acceptable to the neighbors, especially if the owner is willing to share the generated power.

However, a diesel generator that hums away every night and requires a weekly visit from a fuel truck is frowned upon by most neighbors. In many cases, it is considered to be a sign of failed infrastructure similar to the situation that existed in Baghdad in 2005. Solar cells are almost always acceptable, unless their installation requires removing trees to allow the sun to shine directly on the panels.

The desire to have generation in close proximity to the communities where it will be used is strongly held until the actual implementation starts and residents realize that it will change their neighborhood and environment. Again, there is going to have to be a wide-ranging discussion that includes a broad spectrum of people to set rules that are reasonable.

Distributed renewables
Run-of-the-river hydro, solar cells and small wind are all distributed generation methods that people accept as renewable and to some extent are willing to support in their community and even in their own neighborhood. Run-of-the-river hydro uses slow-turning river-bottom turbines that look like old-style ship propellers. Because they turn slowly, very little life in the river is disturbed. They can be installed in local creeks and rivers, even if the water is not always present. There is no impoundment of water, so there is little disturbance of the actual flow of the river.

Another version of run-of-the-river technology is using small waterfalls in mountainous regions that may be season-able in nature. These facilities seek to capture the water before it falls and return it to the area where it would fall. The presence of piping and turbines are the only sign that anything has changed.

Neither type of run-of-the-river hydro is without drawbacks, but both seem better than conventional dams from an environmental standpoint. Most people understand solar cells and what they entail for installation. Small wind comes in an array of choices, from vertical windmills that look like upside-down egg beaters or pop cans with the sides cut open, to old-style farm windmills, to modern-looking propellers in the air. Each has its own advantages and drawbacks.

Distributed non-renewables
Combined heat and power plants that burn natural gas or fuel oil to produce electricity, hot water and space heating can be as much as 98 percent efficient. This is a leading technology in the Netherlands and Demark. Likewise, diesels have been around forever and are the basis for most of the demand response in the major East Coast electricity markets. Instead of turning off the use of energy, most businesses that participate in demand response programs can make enough money to make it worthwhile to run the diesel instead when the power price is high enough. Non-renewables offer something that most of the renewables don't: namely, the ability to schedule generation when you want power.

If you want electricity on demand, then you need schedulable resources, since it is today impractical to store electricity as electricity. The more generation in an area that is pushed into the non-schedulable boxes, the more the use of electricity has to be driven by the available generation techniques. In an extreme case, this will mean that in one minute, enough power exists to wash the clothes, while in the next, there is not sufficient power to complete the task. Potentially, this could necessitate a complete redesign of equipment to use flywheels to ride through the loss of generation. This has already been done by many people who have built houses off the grid.

Figuring out how to coordinate generation with demand is the subject of a large number of ongoing research projects, many of which are focused around "smart homes."

Smart homes and businesses
Not only are homes going to get "smart" in the near future, but so are businesses and appliances. Developing technology to allow homes, appliances and businesses to communicate about energy needs, prices and schedules is an important step in changing the industry paradigm. If these devices can understand the amount of power that is available without the intervention of the homeowner and the home or business owner can set priorities for energy use, the systems can largely manage themselves.

Some are fearful of having appliances and homes that are intelligent, and they often point to old science fiction films as the reason why. After all, who wants a HAL9000 running their lives? Others are very worried about privacy and the loss of it. Getting to the "iPod" of smart homes that homeowners are comfortable with will take time and research into how people want to interact with their energy equipment. This is not a single-step process, but rather a journey that may take a decade or more to perfect a first-generation technology that large numbers of people are willing to adopt.

Smart grid
Beyond the home is the infrastructure that connects the homes and businesses to the electrical generation equipment. This set of poles, wires and transformers will be even more critical in the future as people attempt to balance a system that has even more variability than the system they are used to today. Offering surplus power to a neighbor-or a neighboring state-in return for electricity from them when you are running short will be a minute-by-minute or hour-by-hour process. The more connected people are and the more efficient the connection system is, the better chance there is of using more renewables as a source of energy in the future. The smart grid is a complex topic that encompasses literally hundreds of technologies.

 


 

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