Two Perspectives on Household Energy Use

 

Source: U.S. Energy Information Administration, Annual Energy Review 2011, Table 2.1b.

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Electricity and natural gas now account for approximately equal amounts of the energy consumed on site in U.S. households. But because it takes on average nearly three units of energy from primary fuels such as coal, natural gas, and nuclear fuel to generate one unit of electricity, increased electricity use has a disproportionate impact on the amount of total primary energy required to support site-level energy use. Electricity-related losses explain the difference between energy consumption in the residential sector as measured by energy consumption on site (left) and energy consumption of primary fuels (right).

Unlike natural gas consumption in the residential sector, which has remained nearly flat for decades, and consumption of other fuels, which has declined, the use of electricity in the residential sector has grown. Electricity powers dozens of machines in homes, including heating and cooling equipment, cooking appliances, refrigerators, dishwashers, and an ever-growing number of home entertainment and rechargeable devices. Although many electric end-uses are covered by federal efficiency standards or voluntary programs like ENERGY STAR®, increases in both the percentage of homes with those devices and, in the case of electronics like televisions and computers, the number of devices per household have offset efficiency gains in residential electricity use.

For example, according to EIA's Residential Energy Consumption Survey (RECS) in 1993, only 22% of households had three or more televisions, and less than 45% used central air-conditioning. By 2009, nearly half of all homes contain three or more televisions, and more than 60% use central air-conditioning.

Increasing electricity consumption within homes has broader implications for total energy use. In 1950, electricity generators used nearly five units of primary energy to generate one unit of electricity. By 2011, changes in the generation mix and improvements in technology lowered this value to 3.1 units of primary energy for every unit of electricity.

Historical time-series data for commercial, industrial, and transportation are available in the Annual Energy Review, and projections are available in the Annual Energy Outlook.

Source: EIA

Coalition Proposes 50% Renewable Energy Standard

A coalition representing more than 30 organizations from clean energy, labor, and business have initiated the "Minnesota Clean Energy & Jobs" campaign by proposing that half the power produced in the state be from renewable sources by 2030, accoding to an article in the St. Paul Pioneer Press.  The group is calling for 40 percent to be from renewable sources such as wind energy with the other 10 percent from solar, saying that the wind industry already has created 3,000 jobs in Minnesota and that the new solar standards would create 2,000 more.  In 2007, Minnesota set a standard of roughly 25 percent from renewable sources by 2025. Read more

House Members Ask for Wind PTC Clarification

Thirty members of the U.S. House of Representatives Sustainable Energy and Environment Coalition (SEEC) have sent a letter to the Internal Revenue Service (IRS) and Department of the Treasury encouraging them to act swiftly in issuing guidance to clarify the eligibility qualifications for the renewable energy tax credit that was extended in the American Taxpayer Relief Act. Lawmakers extended the renewable energy production tax credit (PTC) as part of the “fiscal cliff” deal signed into law on January 2, 2013.  This extension altered the language of the PTC to apply to projects that have “commenced construction” instead of projects that have been “placed-in-service.”

Source: House of Representatives SEEC

Xcel May Add More Wind Power

Minneapolis-based Xcel Energy reportedly is considering adding more wind power to take advantage of the recently-extended production tax credit (PTC) program. According to the StarTribune, the company said it is soliciting proposals from developers for up to 200-megawatts of additional wind energy. Xcel currently has the most wind power of any U.S. utility, partly due to the Minnesota Renewable Energy Standard statute which requires it to increase the percentage of its overall power provided by renewables. The company stated it is well ahead of meeting those requirements. No information was provided about possible locations of new wind farms, but the company stated it would be open to proposals that serve its customers in Minnesota, South Dakota, North Dakota and Wisconsin. Read more

Renewable Energy Standard Update

According to a recent report released by the Minnesota Department of Commerce's Division of Energy Resources, all 16 of the utilities subject to the Minnesota Renewable Energy Standard have demonstrated compliance with the 2011 requirements and are on track to comply with 2012 goals. The report is entitled Progress on Compliance by Electric Utilities with the Minnesota Renewable Energy Objective and the Renewable Energy Standard and is prepared for the Minnesota Legislature once every two years.

Minnesota’s Renewable Energy Standard (RES) statute, amended in 2007, requires that all electric utilities, with the exception of Xcel Energy, provide 25 percent of their total Minnesota retail electric sales from renewable sources by 2025; Xcel Energy’s requirement is 30 percent by 2020. The RES is balanced to protect ratepayers from paying excessive amounts for renewable energy, especially if utilities can show they are unable to meet the RES. 

All utilities, with the exception of Xcel Energy, were required to provide 12 percent of their total Minnesota retail electric sales from renewable sources by the end of 2012. Xcel, which provides about half of the state’s electricity, had to generate 18 percent of its retail sales from renewable sources by the close of 2012.

Actual 2012 compliance figures will not be known until May 2013, when final figures will be reported to the Minnesota Public Utilities Commission. Year-to-date 2011 generation was used to estimate the ability to comply with 2012 requirements.

The Renewable Energy Standard progress report (.pdf)

Source: Minnesota Department of Commerce

Solar Farm Goes Online Near Slayton

A solar energy project built by Ecos Energy in a former cornfield outside of Slayton, Minn, began producing power last week, according to a report in the StarTribune. The project consists of 7,040 solar panels arranged in 32 rows with an output capacity of 2 megawatts. The power is being purchased by XCel Energy, which is planning to study how solar energy and intermittent energy from nearby wind farms can complement each other. In Minnesota, twice as much solar capacity was installed in 2012 compared with the prior year, with more than 250 projects of varying sizes coming online, according to the StarTribune report. Read more

Report Says Ethanol Boosted State Economy in 2011

A new report from the Minnesota Department of Agriculture shows the state's ethanol industry produced over $5 billion in total economic activity last year, according to an article in today's Pioneer Press.  In addition to supporting more than 12,600 jobs, the ethanol industry added $912 million to the value of the state's corn crop in 2011. Much of the production, however, was to take advantage of the federal production tax credit before it's year-end expiration, and resulted in a market glut which lowered demand for ethanol in the first half of 2012, the report pointed out.  Read more

Plants' Role in CO2 Management Questioned

According to a new University of Minnesota study, plants may not be able to absorb as much of the increased levels of carbon dioxide in the air as originally thought. The study shows that while plants can absorb and benefit from large amounts of carbon dioxide, they may not get enough of the required nutrients from typical soils to absorb the levels of  CO2 that scientists previously believed possible, which raises questions about their role in mitigating fossil-fuel emissions. The study was published in the current issue of journal Nature Climate Change. Read mores 

New Report on Economic Benefits of Wind Energy

A new study concludes that recent wind energy projects increased both personal income and employment in the counties included in the research, which was done by the USDA Economic Research Service, the National Renewable Energy Laboratory and Lawrence Berkeley National Laboratory.  The researchers looked at economic data from 1,009 counties in 12 windy states, including North Dakota, South Dakota and Minnesota. Among the sources of economic benefits analyzed in the study were direct employment during construction and operation, lease payments to landowners, demand for local goods and services, tax payments and other spending. Read more

New Energy Storage Technology Announced

RICHLAND, Wash. – A Washington state firm with a 27,000 square foot manufacturing and design facility in Mukilteo has signed a license agreement with Battelle to further develop and commercialize a type of advanced battery that holds promise for storing large amounts of renewable energy and providing greater stability to the energy grid.

The agreement with UniEnergy Technologies LLC is intended to advance and commercialize "redox flow" battery technology.

Developing a technology that can smoothly integrate energy from variable and intermittent sources — such as wind and solar power — onto the electricity grid while maintaining grid stability has proven challenging. First developed in the 1970s, redox flow batteries are one type of storage technology that has shown the ability to meet this challenge. But until now, these batteries have been limited in their ability to work well in a wide range of temperatures, their relatively high cost, and their limited ability to store energy, otherwise known as energy density.

Recently however, with funding from the Energy Department's Office of Electricity Delivery & Energy Reliability, researchers at DOE's Pacific Northwest National Laboratory have made significant progress in improving the performance of redox flow technology.

Redox flow batteries are a type of rechargeable battery that stores electrical energy in two tanks of electrolytes, which are then pumped through a reactor to produce energy. The PNNL-developed vanadium electrolytes incorporate two novel approaches to overcome the limitations of previous generations of redox flow batteries. The result is a dramatically improved operating range, higher energy density and lower cost for vanadium redox flow batteries.

The licensing agreement with UniEnergy will lead to enhanced commercial products for utilities, power generators and industry that will enable the energy grid to operate more reliably and efficiently, with better integration of  renewable resources, such as energy produced by wind and the sun.

"The redox flow battery is well-suited for storing intermittent, renewable energy on the electricity grid. The technology can help balance supply and demand, prevent disruptions and meet the grid's varying load requirements," said Imre Gyuk, energy storage program manager at DOE's Office of Electricity Delivery & Energy Reliability in Washington, D.C.

"Redox flow batteries can also help utilities during times of peak demand on the grid, providing additional power when it is needed," he added. "Successful commercialization of DOE-sponsored technology development, such as this, is vital for creating the grid of the future, and sustaining U.S. leadership in advanced technology."

Source: Pacific Northwest National Laboratory