Renewable Energy Consulting – PPA Partners, LLC

May 17, 2010 11:29 PM

BY STEPHANIE A. WILKEN – SUN STAFF WRITER

One future renewable energy project will be the first of its kind — and it’s one step closer to coming to Yuma County after the Board of Supervisors meeting Monday.

The Yuma Sun previously reported on a planned solar research project at Arizona Western College.

The project will include 5 1-megawatt systems and cover five different types of solar collection that will enable researchers to have data that’s never before been produced, said Bruce Mercy with PPA Partners Inc. (PPA), the lead contractor on the project.

“Nowhere in the country, no where in the world is there a (research) demonstration like this,” Mercy said.

Monday, supervisors authorized PPA to pursue $22 million in Yuma County Recovery Zone Facility Bonds to help finance the $30 million project. The money is a bond that will be repaid by PPA and is part of the American Recovery and Reinvestment Act of 2009.

Because the five different systems can run simultaneously and will be in the same area, it will be a unique research facility for solar, Mercy said. And all of the systems are designed for a utility-sized demonstration and test, he said.

PPA will share the data with the college, which could also entice research teams to come.

“The data from this field is probably one of the most valuable components of this project,” he said. “(It’s) one of the greatest carrots that we can put out there.”

There will also be an opportunity for solar manufacturing facilities in the future, Mercy said, citing that manufacturing facilities generally locate within 60 miles of research facilities.

In addition, Mercy said the college is working on developing curriculum including advanced degrees because of the project.

PPA will fund the $30 million through two revenue sources: one from revenues from Arizona Public Service, and another from a federal tax grant.

In addition to being the largest solar array at a college or university, the project at AWC will supply the college with 100 percent of its power — a major cost savings to the college.

In 10 years, the project is expected to save the college $3.5 million, in 15 years save $15.4 million, and in 30 years, the college is expected to save almost $54 million.

And with the bright, sunny days in Yuma County, it’s the perfect place to house the project, Mercy said.

“There should be solar on everything here,” he said.

The project, he said, will have a great impact on solar research.

“We’re taking it to a degree not even considered up to this point.”

The project is expected to go online Dec. 1.

Stephanie A. Wilken can be reached at swilken@yumasun.com or 539-6857.

Source: Yuma Sun

Hydrogen is the simplest element. An atom of hydrogen consists of only one proton and one electron. It’s also the most plentiful element in the universe. Despite its simplicity and abundance, hydrogen doesn’t occur naturally as a gas on the Earth – it’s always combined with other elements. Water, for example, is a combination of hydrogen and oxygen (H₂O).

Hydrogen is also found in many organic compounds, notably the hydrocarbons that make up many of our fuels, such as gasoline, natural gas, methanol, and propane. Hydrogen can be separated from hydrocarbons through the application of heat – a process known as reforming. Currently, most hydrogen is made this way from natural gas. An electrical current can also be used to separate water into its components of oxygen and hydrogen. This process is known as electrolysis. Some algae and bacteria, using sunlight as their energy source, even give off hydrogen under certain conditions.

Hydrogen is high in energy, yet an engine that burns pure hydrogen produces almost no pollution. NASA has used liquid hydrogen since the 1970s to propel the space shuttle and other rockets into orbit. Hydrogen fuel cells power the shuttle’s electrical systems, producing a clean byproduct – pure water, which the crew drinks.

A fuel cell combines hydrogen and oxygen to produce electricity, heat, and water. Fuel cells are often compared to batteries. Both convert the energy produced by a chemical reaction into usable electric power. However, the fuel cell will produce electricity as long as fuel (hydrogen) is supplied, never losing its charge.

Fuel cells are a promising technology for use as a source of heat and electricity for buildings, and as an electrical power source for electric vehicles. Fuel cells operate best on pure hydrogen. But fuels like natural gas, methanol, or even gasoline can be reformed to produce the hydrogen required for fuel cells. Some fuel cells even can be fueled directly with methanol, without using a reformer.

In the future, hydrogen could also join electricity as an important energy carrier. An energy carrier moves and delivers energy in a usable form to consumers. Renewable energy sources, like the sun and wind, can’t produce energy all the time. But they could, for example, produce electric energy and hydrogen, which can be stored until it’s needed. Hydrogen can also be transported (like electricity) to locations where it is needed.

Geothermal energy is heat from the Earth. It’s clean and sustainable. Geothermal energy resources can range from the temperature effects found in the first ten feet underground to the hot water and the hot rock found a few miles beneath the Earth’s surface, or even deeper to the extremely high temperatures of molten rock, or magma.

In most locations the upper 10 feet of the Earth’s surface maintains a nearly constant temperature of between 50° to 60°F (10° and 16°C). Geothermal heat pumps can tap into this resource to heat and cool buildings. A geothermal heat pump system consists of a heat pump, an air delivery system, and a heat exchanger, (a system of pipes buried in the ground near the building). In the winter, the heat pump removes heat from the heat exchanger and pumps it into the indoor air delivery system. In the summer, the process is reversed, and the heat pump moves heat from the indoor air into the heat exchanger. The heat removed from the indoor air during the summer can also be used to provide hot water.

In the United States, most geothermal reservoirs of hot water are located in the western states, Alaska, and Hawaii. Wells can be drilled into underground reservoirs for the generation of electricity. Some geothermal power plants use the steam from a reservoir to power  turbines or generators, while others use the hot water to boil a working fluid that vaporizes and then turns a turbine. Hot water near the Earth’s surface can be used directly for heat. Direct-use applications include heating buildings, growing plants in greenhouses, drying crops, heating water at fish farms, and several industrial processes such as pasteurizing milk.

Hot dry rock resources occur beneath the Earth’s surface at depths of 3 to 5 miles and at lesser depths in certain areas. Access to these resources involves injecting cold water down one well, circulating it through hot fractured rock, and drawing off the heated water through another well. Currently, there are no commercial applications of this technology. As well, existing technology does not yet allow for the recovery of heat directly from magma, the deepest and most powerful geothermal energy resource.

Many technologies have been developed to take advantage of geothermal energy. NREL currently performs research to develop and advance technologies for the following geothermal applications:

Geothermal Electricity Production

Generating electricity from the earth’s heat.

Geothermal Direct Use

Producing heat directly from hot water within the earth.

Geothermal Heat Pumps

Using the shallow ground to heat and cool buildings.

We have been harnessing the wind’s energy for hundreds of years. From the picturesque windmills of Holland to farms in the United States, windmills have been used for pumping water and grinding grain for centuries. Today, the windmill’s modern equivalent – a wind turbine – can use the wind’s energy to generate electricity.

Wind turbines, are mounted on a tower at 100 feet or more above ground, where they can take advantage of the faster and less turbulent winds. Turbines catch the wind with their propeller-like blades, which is usually comprised of two or three blades mounted on a shaft forming a rotor.

A blade acts much like an airplane wing. When the wind blows, a pocket of low-pressure air forms on the downwind side of the blade. The low-pressure air pocket then pulls the blade toward it, causing the rotor to turn. This is called lift. The force of the lift is actually much stronger than the wind’s force against the front side of the blade, which is called drag. The combination of lift and drag causes the rotor to spin like a propeller, and the turning shaft spins a generator to make electricity.

Wind turbines can be used as stand-alone applications, connected to a utility power grid or even combined with a photovoltaic (solar) system. For utility-scale sources of wind energy, a large number of wind turbines are usually built close together to form a wind plant. Several electricity providers today use wind plants to supply power to their customers.

Stand-alone wind turbines are typically used for water pumping or communications. However, homeowners, farmers, and ranchers in windy areas can also use wind turbines as a way to cut their electric bills. Small wind systems also have potential as distributed energy resources.

Solar cells convert sunlight directly into electricity. Solar cells are made of semiconducting materials similar to those used in computer chips. When sunlight is absorbed by these materials, the solar energy knocks electrons loose from their atoms, allowing the electrons to flow through the material to produce electricity. This process of converting light (photons) to electricity (voltage) is called the photovoltaic (PV) effect.

The performance of a solar cell is measured in terms of its efficiency at turning sunlight into electricity. Only sunlight of certain energies will work efficiently to create electricity, and much of it is reflected or absorbed by the material that makes up the cell and panel. Because of this, a typical commercial solar cell has an efficiency of 15%-about one-sixth of the sunlight striking the cell generates electricity. Low efficiencies mean that larger arrays are needed, and that means higher cost. Improving solar cell efficiencies while holding down the cost per cell is an important goal of the PV industry, NREL researchers, and other U.S. Department of Energy laboratories, and they have made significant progress. The first solar cells, built in the 1950s, had efficiencies of less than 4%.

Solar cells are typically combined into modules that hold about 40 to 72 cells; a number of these modules are mounted in arrays that can measure up to several meters on a side. These flat-plate PV arrays can be mounted at a fixed angle facing south, or they can be mounted on a tracking device that follows the sun, allowing them to capture the most sunlight over the course of a day. Several connected PV arrays can provide enough power for a household; for large electric utility or industrial applications, hundreds of arrays can be interconnected to form a single, large system.

Thin film solar cells use layers of semiconductor materials only a few micrometers thick. Thin film technology has made it possible for solar cells to now double as rooftop shingles, roof tiles, building facades, or the glazing for skylights or atriums. The solar cell version of items such as shingles offer the same protection and durability as ordinary asphalt shingles.

Some solar cells are designed to operate with concentrated sunlight. These cells are built into concentrating collectors that use a lens to focus the sunlight onto the cells. This approach has both advantages and disadvantages compared with flat-plate PV arrays. The main idea is to use very little of the expensive semiconducting PV material while collecting as much sunlight as possible. But because the lenses must be pointed at the sun, the use of concentrating collectors is limited to the sunniest parts of the country. Some concentrating collectors are designed to be mounted on simple tracking devices, but most require sophisticated tracking devices, which further limit their use to electric utilities, industries, and large buildings.