Study Finds the Storage of Solar Power Increases Consumption and Emissions

Solar panels TexasRecent research from the University of Texas at Austin suggests that the greatest environmental and economic benefits from solar power come from sending excess solar power to the utility grid instead of storing it on-site for later use.

The paper examines the costs and benefits of adding energy storage to homes with existing solar panel systems. While the number of American households with rooftop solar panel installations has rapidly reached the level of 1 million, many fewer homes have a means for storing any excess solar power that is produced. However, there is a growing interest in the on-site storage of excess solar energy, and this study sheds some light on the factors involved in this decision.

Solar Power Still Effective Without Storage

The main thrust of the paper’s findings is that there is no need to have a storage system in place to benefit from the installation of solar panels. One of the most common negative myths about solar energy is that it requires the installation of an additional storage system for when the sun is not providing adequate electricity. However, it is actually more efficient to merely switch to grid energy during times when solar is inadequate rather than storing excess solar power.

The researchers found that the storage of solar power for nighttime use will actually increase a household’s energy consumption, compared to the use of solar panels without any form of storage, due to the consumption of additional energy caused by the charging and discharging of the storage unit. While an increase in energy consumption as a result of storage is not surprising, the level, from 8% to 14% over the span of one year, was much higher than anticipated.

Storage of Solar Power Leads to Greater Environmental Impact

The study discovered that the addition of storage indirectly increased overall emissions of carbon dioxide, nitrogen dioxide and sulfur dioxide. The increased emissions are due to the increased energy consumption that is required to compensate for the inefficiency of household storage. However, since storage will affect the time of day that a household will draw electricity from the grid, it will also reduce emissions in that way.

The benefit for utility companies is more clear. The storage of solar energy reduced peak grid demand by 8% to 32%, as well as the magnitude of solar power fed into the grid by 5% to 42%, which is beneficial for the utility as it will reduce the amount of required capacity.

Overall the analysis demonstrated that the storage of solar power now offers less environmental benefits than sending it into the grid, since the energy that is lost to inefficient storage will ultimately be covered by electricity from the grid that is produced using a high proportion of fossil-fuels.

See also: Solar In, Coal Out, In Texas Electricity Grid


Solar In, Coal Out, In Texas Electricity Grid

Going forward almost all new electricity in Texas will come from renewable energy sources – primarily solar energy.  This is according to a report released by the agency responsible for maintaining the Texas electricity grid.  Once the dominate sources of electricity in Texas, coal has been on its way out for a number of years.  Due to a combination of market forces and federal regulations, coal can no longer compete with other sources or power.

The report looks at a number of possible scenarios to project the makeup of the Texas electricity market over the next 15 years.  The scenarios include High Economic Growth, Recession, and Extended Extreme Weather.

Under every scenario solar energy is the predominate theme. It seems that solar energy is finally having its moment in the Texas sun.  Today the state gets a tiny percentage of its energy from solar power.  According to the latest projections, this amount will soar to around 17% in the next 15 years.  Practically all of the gains in solar will come at the expense of coal.

Solar energy projections Texas

The Texas deregulated electricity market is designed to allow competition to keep electricity rates low.  The largest component of electricity rates is the wholesale price of electricity paid to the producers from retail electricity providers.  The fact is, electricity generated by solar power is now cheap and getting cheaper.

This is not just a Texas phenomenon.  Worldwide, solar energy is expected to be the cheapest source of new energy over the next 15 years.  Between now and 2040, 43% of new capacity worldwide is expected to come in the form of solar.

Pressure on coal is not coming just from competition from clean energy sources.  Tough federal regulations will continue to have their intended effect over the coming years.   Over the next 5 years alone, 5 gigawatts of coal power will be leaving the Texas electricity grid because of the EPA’s “regional haze rule”.  Against this, 14 to 28 gigawatts of solar power are expected to come on line in Texas over the next 15 years.

See Also:  Enough Electricity In Texas For Spring As Renewable Energy Surges

See Also: Wind Energy Provides Cheap Electricity In Texas


Solar Power Generating Capacity Up, Reports EIA

Solar power in Texas electricityThe Energy Information Administration (EIA), an agency of the federal government that collects, analyzes, and reports information about the energy sector to help create effective energy policy and to educate the public, has released a report about solar electricity generation in the United States. The news is impressive: Capacity for generation of electric power from solar has risen dramatically over the past four years, from 2,326 megawatts in 2010 to 12,057 MW in 2014, going from .22% of the power generation capacity of the United States to almost 1.13%, an amazing 418% growth rate.

If one percent or so sounds miniscule, consider that it means more than one in 100 people in the country can get their power from a clean, renewable source. That’s over 3.2 million people, at present, and if solar were to maintain its meteoric growth rate of over 100% per year, that capacity would more than double every year, providing two-thirds of the country’s capacity in six short years. While it’s unlikely that capacity will burgeon that dramatically, prospects for continued robust growth look good, owing mainly to the sharp decrease in prices for solar power generation systems in recent years, coupled with increased government incentives.

The EIA report analyzes data from three different sources of solar power generation: Residential and commercial photo-voltaic (PV) systems that are connected to the grid via net metering; “utility-level” (defined as producing more than one megawatt) PV systems; and utility-level solar thermal systems. Net metered systems have increased annually by over 1,000 MW since 2010, and there are many incentives at the state level to encourage further growth. Net metering, which allows individual customers to sell the excess energy produced by their systems back to the power companies, is about equally divided between residential and commercial applications (there are also some self-sufficient systems that are “off the grid”–not net metered–but these were not counted among the data).

In the two utility-level categories, solar PV applications at the utility level finally surpassed the net metered PV capacity in 2013, currently accounting for more than 5,500 MW. Not surprisingly, sunny California and Arizona are the leading states in this sector, but somewhat-sunny North Carolina comes in third, due to statewide incentives. Solar in Texas is still struggling to take hold due largely to a lack of incentives and low electricity rates from traditional sources of power such as natural gas.  Solar thermal systems, which employ the sun’s heat where PV systems use its light, currently lag behind PV, with a generating capacity of about 1,050 MW, but the forecast for growth in this sector is also strong. Because of its storage capacity, solar thermal can supplement PV on cloudy days or at night. Several new solar thermal plants were brought online recently, more than doubling the prior capacity, and plans are in the works for further development, both in solar thermal and PV, as well. It is anticipated that net-metered solar will expand accordingly, making solar a robust sector for growth.

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Texas Clean Energy Coalition Report Provides Incentive For Renewable Energy

The clean energy advocacy group Texas Clean Energy Coalition (TCEC), in a new report entitled Exploring Natural Gas and Renewables in ERCOT II, Future Generation Scenarios for Texas, provides an in-depth analysis of the future energy supply prospects of the State of Texas, based on existing technology, with a realistic and somewhat conservative analysis. It is the first report of its kind, overshadowing previous somewhat simplistic modeling, and utilizing high-end modeling techniques and highly developed statistical analysis.

The study examines the current Texas electricity grid, based on the current power supply supplied through the Electric Reliability Council of Texas (ERCOT) —power grid. ERCOT manages electricity provided to 23 million Texas residents, supplying 85% of the state’s electric load. Varied energy sources are considered in the present grid, from coal-fired electric plants, electricity supplied by natural gas, as well as renewable energy’s current contribution to Texas power in the form of wind-powered electricity and solar energy.

Texas is already the state producing the most wind-powered electricity in the country, with more than 12,000 megawatts of current capacity, more than double that of any other state in the U.S.  40% of Texas’ electricity is currently produced from natural gas plants, while the state itself is the leading producer of natural gas in the United States. Additionally, the state of Texas has an abundance of natural sunlight all year round, which makes increased reliance on electricity through solar power both a reliable and economically advantageous proposition. Texas currently gets 10% of its energy from renewable sources, and the study suggests an increase in reliance on renewable resources prospectively reaching between 25% to 43% over the 20 year scope of the report.

Using various scenarios and models with major factors considered such as possible public environmental policy, the likelihood of a slight decrease in the cost of producing electricity through renewable sources, relative stability in the cost of natural gas vs. significantly higher prices for natural gas, and the required power reserve margin, the topic is examined not in the context of a “tree huggers” utopia, but realistically, and more importantly, in terms of costs and profits for power companies—how planning for the future, based on numerous likely scenarios and variables, may make investing in facilities for renewable resources along with an increase in reliance on natural gas powered plants, a strategy with long-term economic benefit for the state. The report, then, takes a pragmatic approach rather than taking on the tone of an environmental crusade.

A by-product of the report, is that it can provide incentive for policy makers who are interested in reducing reliance on “dirty” energy, such as supplied by coal powered plants, to pursue a stricter policy in reduction of carbon emissions, with a resultant increase in reliance on wind, solar and natural gas. Such an incentive for policy makers is not directly insisted on by the report, but it could be a beneficial by-product, in that a stricter policies on carbon emissions, one of the scenarios explored here, while perhaps making coal-fired plants less profitable, or in the strictest scenario, making them unprofitable and essentially forcing coal-operated plants closed, would not necessarily result in higher energy prices or loss of profit as a whole to the industry. With planning, low-cost energy could be maintained with clean energy supplies, alongside a stable profit margin for power producers, by investing more heavily in renewable energy resources, alongside an increase in reliance on the clean energy produced by natural gas fired power plants.

Through the study all involved can take a realistic look at the next 20 years of increasing energy needs in Texas, and while the study does not focus on environmental benefits, the thrust of the report is that there are both economic benefits to a greater investment in renewable energy and gas, with the implied side benefit of less impact on the environment (less pollution). If power companies can maintain profits while saving the environment, why not? It is a win-win situation for everyone involved. This is especially poignant in view of the fact that Texas’ energy requirements are expected to double over this same 20 year time period, placing a tremendous demand on existing resources. The topic of how to meet future energy demands is something that needs to be addressed regardless of the one’s environmental position, so the question becomes, simply, which direction to point the arrow. The report implies that pointing in the direction of clean energy makes economic sense for everyone involved by adequately covering a wide range of possible scenarios including future technological developments.


See Also: Microsoft Makes Large Texas Wind Power Purchase
See Also: Texas State Senator Pressures ERCOT to Leave Reserve Margins Unchanged




Photovoltaic Far More Efficient Than Biofuel For Electricity Production

According to research performed by University of California – Santa Barbara Bren School of Environmental Science & Management and published in the journal Environmental Science & Technology, photovoltaics outperform biomass in just about every metric – and it isn’t even close.

The research was done to address the question of how to most efficiently power alternative fuel or battery powered electric vehicles.   It’s an important question considering electric vehicles are ostensibly better for the environment than traditional gasoline powered vehicles.

When you switch from a gas powered vehicle to an electric vehicle pollution from tailpipe emissions is effectively eliminated.  But things aren’t as straight forward as that.  The source of the electricity used to charge the electric vehicle’s battery can have a substantial impact on the true environmental cost of your commute.

Most Texas electricity (the vast majority in the U.S in fact) still comes from coal or natural gas.  As a result, the environmental savings of electric vehicles, while still positive, are not as great as they could be.   To truly maximize the impact of electric powered transportation the electricity needs to be sourced from truly clean and renewable energy sources.

The University of California study compares two such potential sources; photovoltaics and biofuel.  Both methods work by extracting energy from the sun.  Photovoltaics achieve this by directly converting solar radiation into electricity while biofuel relies on photosynthesis to extract energy from the sun’s light.   From there, biomass can be used to create fuel (such as corn ethanol) for internal combustion engines or it can be used to generate electricity.

One of the study’s findings was that acre for acre, solar cells produce around 30 times more electricity than the most efficient biofuel crops.  This means the land use efficiency of solar vs. biofuel is better by a factor of 30.   For some of the least efficient crops, the land-use efficiency of solar power is about 200 times greater.  Compounding the effect, consider that solar cells don’t have to be placed on agriculturally valuable land.  They can be installed within cities and on roof tops.

Adding to the case for solar over bio is the fact that this gap in efficiency is likely to continue to widen.  The best photovoltaic technology currently converts about 10 percent of the solar radiation it receives into energy.  As the technology continues to advance this conversion ratio is only likely to improve, even as prices come down.  Biofuels however are hamstrung by the fundamental limitations of photosynthesis which only converts about 1% of the sun’s radiation it receives into energy.

See Also: Data Shows Electric Vehicles Could Strain Electricity Grid
See Also: Have We Seen The Peak In Carbon Emissions?