Renewables: Other | altenergymixintx

REnewable energies

"The path towards sustainable energy sources will be long. America cannot resist this transition, we must lead it."

- President Barack Obama

To most, Texas seems like an obvious choice for solar energy to be used. In fact, Texas has ranked as the number one state with potential for solar energy. (1) However, the current generation capacity of solar energy in Texas is around 200 MW. (2) Solar energy is being radically underutilized in the state. This is likely due to the lack of efficient subsidies or incentives that there are for producing solar energy. Net-metering programs have been a large part of the success for solar energy in other states and to succeed in Texas, solar energy would need much more funding and most likely government intervention.

There are two types of solar technologies that can be used to generate electricity. First is the photovoltaic, which converts light into electricity by using a semiconductor (usually silicon). The other technology is concentrated solar power, which collects heat from sunlight using mirror arrays (11).

If solar is so clean, why hasn't everyone caught on to using this energy source?

First, many people still believe solar panels are extremely expensive but in fact, solar costs have dropped significantly over the past couple of years. "The cost of solar-generated electricity has fallen 78% in the past five years due to a combination of factors that include technology improvements, financing innovations, and general economies of scale. Here in Texas, average installed residential and commercial photovoltaic system prices have fallen by 20% just in the past year." (3) This decrease in price gives the perfect incentive for an increase in use of solar power in Texas. Solar panels are a great investment more now than ever. Not are they just a great way to save money, but also help the economy. Solar power in Texas employs nearly 7,000 people and this number is expected to continue growing.

Solar

Biomass

Geothermal

Geothermal energy is created by harvesting the heat produced by the earth's mantel layer. This heat is then used to convert water to steam that will power a steam-electric generator. Geothermal energy does not give off any pollutants, and it does not involve issues with intermittency like wind and solar energy do. Many of the wells dug for oil or natural gas could potentially be used to tap into geothermal energy. There had been speculation that the water that was produced as a byproduct of these wells could be used since the water was often at temperatures above 200 degrees Fahrenheit (1). However, there has not been much funding for research into the viability of geothermal energy in Texas. There was a surge of interest in the 70s and 80s, but harnessing the energy from the water leftover from the oil and gas well proved to be more difficult than was initially anticipated. Furthermore, oil and gas prices fell so geothermal technologies lost most of the funding that they had initially been relying on. As of now, geothermal is a long way from being a viable option for electricity generation in Texas.

Hydroelectric

Hydroelectric energy is energy that is produced from the use of flowing or falling water to turn a turbine, which then powers a generator. Hydroelectricity is another renewable source of energy that results in little to no pollution. Hydroelectric power has been popular for centuries, and as such the technology is fairly advanced in most places. Most developed countries have already completely utilized their hydroelectric power sources. Texas gets less than 1% of its electricity from hyrdoelectric sources (1). This is largely due to the fact that surface water in Texas is limited and the rivers flow very intermittently (2). Hydroelectric power has mainly been used as an extra source of electricity during times of peak demand, but it isn't used for much else outside of that. It is not a viable option as a renewable source of energy for a substantial amount of the energy demand in Texas.

Source: seco.org

Source: University of Texas

Most wind turbines consist of three blades attached to a steel shaft. Wind turns the three blades and this mechanical energy is converted into electrical energy by providing power to a generator. Wind turbines range in size from 80 feet tall that can power a single home to utility-scale turbines that are over 260 feet tall and power hundreds of homes (1). Wind energy does not result in the release of greenhouse gases, and windmills don't require extensive plots of land. The main drawback of wind energy is its intermittency. However, this is proving to be less of a problem in Texas. Most regions in Texas have average wind speeds that are well within the range necessary to power wind mills.

Texas ranks first in the country for both installed and under construction wind capacity, while supporting over 17,000 wind related jobs and providing over $26 billion in capital investment (2). Wind energy has proven to be essential to the source of renewable energies within the state of Texas. Wind energy accounts for more than 10% of the renewable electricity generation in Texas (3). Texas is home to 16,406 MW of installed wind capacity. In 2014, wind energy provided 9% of all in-state electricity-equivalent to 3.6 million homes (2). The proposal of the Competitive Renewable Energy Zones power transmission project in 2008 has largely contributed to the growing success of wind energy in Texas. The CREZ project called for new transmission lines that span nearly 3,600 miles and will be able to send 18,500 megawatts of wind power across the state of Texas. (4) However, this project did not come with a cheap price tag, nearly $7 billion, a price that will be paid by adding on a fee to Texans’ utility bills.

Wind

Solar energy has no emissions associated with producing electricity and uses minimal water (or any water, depending on the type of solar system). Basically all you need is the sun, where there is plenty of in Texas. But, there are some negatives that come along with this energy. One is the solar panel itself; many people do not like the look of them both in a farm or on their actual house. Many home owners associations discourage the installation of these and at one point even banned them. It is now a difficult and lengthy process to gain the permission to install solar panels in certain suburbs.(4) Another disadvantage is that centralized solar plants take up a lot of space because this type of power has a low energy density so it requires a relatively large number of panels. This is definitely a negative considering we are trying to save the environment rather than clear out more land. Centralized solar plants are also not as efficient as decentralized solar. Roughly 30% of the electricity is lost in transferal while decentralized uses power where it is directly needed. (5) Probably the biggest downfall to solar energy is intermittency. Solar panels only create energy when the sun is shining bright which obviously leaves the nighttime and cloudy days without sun to generate electricity; natural gas is usually used as a back up source during these times. But, there has recently been a solution to this intermittency problem. Storage batteries, for largescale and smallscale, are currently on the market.

Although expensive at the moment, batteries are continued to be researched and innovated which will cause the battery costs to ultimately drop. It is hard for some to invest in solar now due to these current issues, but as stated above, solar has a bright future ahead. Texas has a number of incentives for solar and other renewables however, net metering is an important one that the state does not mandate. A net metering program allows electric utility customers to install qualifying renewable energy systems that are connected to an electric utility’s distribution system (or grid) on their property to offset their use of electricity from the grid. (6) Forty-four states have mandated this program to help reach renewable goals while utilities in Texas and a few other states have the option to offer it. (7)

Source: solarcellcentral.com (9)

Source: conserve-energy-future.com (10)

Biomass is another name for material from plant and animals that are used to make energy. Biomass essentially has stored energy that can be used to generate electricity. When Biomass is burned, the stored energy is given off as heat. Unfortunately, burning biomass releases carbon dioxide into the air. Types of biomass used to generate electricity come from wood chips, corn, and garbage waste. Biomass has other benefits to Texas if it is used to provide energy for transportation as well it can be converted into a liquid fuel to power cars and trucks, and can also be made from leftover food products such as vegetable oils and animal fat to create biodiesel or ethanol. Biomass has various methods to generate electricity each with an advantage and drawbacks.

Direct-fired :Uses direct biomass, where the boiler’s fuel is 100% biomass and is burned to operate a conventional steam boiler. Materials used in this process are logging residue, and energy crops.

Co-fired: This method uses the same material as “Direct-fired” but a portion of the boiler’s fuel is coal. Adding coal has an effect where toxic emissions are reduced.

Gasification: Biofuel and biomass is converted into CO and Hydrogen by adding high temperature with a controlled amount of oxygen into the fuel.

Pyrolysis: By converting solid biomass into liquid through high temperatures and negligible oxygen, the energy produced can be easily stored and transported to a plant.

Anaerobic Digestion: Captures methane and decomposing biomatter to burn into a power plant.

Among renewable energies for electricity generation in Texas, biomass remains the second largest behind hydropower. Because of the diversity of bio-feedstock in Texas, it is difficult to estimate the production capabilities of biomass energy to generate electricity. Due to competition of wind farms and solar power, currently there is not a big leap to develop technology or add power plants in the state to generate electricity.

Wind power as an alternative to fossil fuels is plentiful, renewable, clean, produces no greenhouse gas emissions during operation, uses little land and virtually uses no water. According to the American Wind Energy Association the annual state carbon dioxide emissions avoided is equal to 25.1 million metric tons, or 5.3 million cars worth of emissions. Additionally, the annual state water consumption savings is equal to 13.1 billion gallons – equivalent to 99.3 billion bottles of water (2). The DOE Wind Vision projects that by 2030 Texas could produce enough wind energy to power 15.4 million average American homes.

Although there are many upsides to wind power there are a few factors that can be seen as drawbacks. As mentioned above, the main drawback in wind energy is its intermittency. For this reason wind energy is used in conjunction with other energy sources to ensure demand is met; in Texas this is usually natural gas, although it can be other renewables or fossil fuels. Those who live near wind farms often complain of the noise disturbance that come from the wind turbines as well as its visual impacts, however, this is why wind farms are not built near residential areas (9). Wind turbines also pose a threat to wildlife. A study from federal wildlife officials estimated that 368,000 birds are killed annually due to wind turbines. Although, it is estimated that house cats kill on average 1.4 billion birds annually (10). As you can see, it is evident that the benefits of wind power far outweigh the disadvantages when compared to fossil fuels such as coal.

Wind energy has gained much momentum throughout the state that now companies such as General Motors are turning to this energy source to help with their day to day operations. Recently, GM signed a 14 year power purchase agreement with EDP Renewables North America for 30 MW of energy from the 250 MW Hidalgo Wind Farm in Edinburg, Texas to power the GM Arlington Assembly Plant in Texas. GM will save $2.8 million in energy costs annually and over the lifetime of the deal GM will avoid 1 million metric tons of carbon dioxide emissions-which is equivalent to the emissions of 112 million of gallons of gasoline consumed. “Our investment is helping accelerate the proliferation of clean energy in Texas and the use of wind as a reliable, renewable source of energy,” said Jim DeLuca, GM executive vice president of Global Manufacturing (11).

http://www.solaripedia.com/13/163/1483/roscoe_wind_farm_blue.html

"Roscoe Wind Complex Largest in World (Texas)"

Other contributors to the growth of wind production in Texas include mandates, such as the Renewable Portfolio Standard, which requires utility companies to source a certain amount of electricity from renewables, has been a huge driver in the increased production of wind energy in Texas (5). Similarly, incentives such as the Production Tax Credit (PTC) and the Investment Tax Credit (ITC), has helped allow for private investments and projects in the production of wind power (6). The Production Tax Credit is a commercial tax credit based on the amount of wind energy generated, whereas the ITC is a tax credit aimed at projects for wind production. The tax credit amount associated with the PTC is $0.023/kWh (7). The costs associated with installing a commercial scale wind turbine can be costly, typically ranges from $1.3 million to $2.2 million per MW of nameplate capacity installed (8). Due to the high upfront costs, tax and other incentives are used to help reduce the cost of wind projects.