Clean Energy

The Energy-Efficient House
Ceiling Fans Clothes Washing Dishwasher Ducts Heating & Air Conditioning Lighting Range Refrigerator Solar Cells Solar Water Heating Televisions Water Heater Windows

Ceiling Fans

By lowering the need for sensible cooling, ceiling fans can save noticeably on air conditioning. One study suggested an 8% cooling savings in a Texas climate if the thermostat set point is raised 4 degrees.

However, this is only valid if the thermostat is indeed turned up. And electricity can be wasted if the fans are left on when one leaves the room or the house. Fans will not make the furniture and the floors any more comfortable.

Clothes Washing

Clothes washing can use more than 10% of the electricity in a single fuel home in the hot and humid climates in the U.S. However, the electricity used by a clothes washer itself is often less than 4% of the electricity used in the overall laundry process. So washing machines are rated by how much energy is used in the total process to heat water, agitate the clothes, spin them mostly dry, and then complete the process with clothes dryers.

The best clothes washer on the market in 2019 saved 75% of the energy compared to the minimum requirement in 2004, when the first federal standard took effect. It also saved 71% of the water used in the average unit sold in 2010, when the first federal standard took effect.

Using cold water for washing and clothes lines for drying eliminates almost all of the energy used for laundry purposes.


Dishwashers use more than 1% of the energy typically consumed in a home in the hot and humid part of the U.S. when water heating is considered.

The best dishwasher on the market in 2019 saved 75% of the water compared to the minimum requirement for a unit sold in 2010, when the first federal standard took effect. The best unit also saved 57% of the energy compared to the minimum requirement for a unit sold in 2004, when the first federal standard took effect.


In general terms, duct sealing and balancing is the most important energy measure you can employ for an old or new house. Ducts in a typical home leak 25% of the conditioned air, which is most of the air leakage in a house. Some poorly built apartment units can leak as much as 45%! With proper sealing, this can be reduced to 10%. “Balancing” air delivery by installing larger ducts to allow more air to enter a room or relief vents that prevents over-pressurized rooms improves comfort and lowers bills.

There are air quality benefits from this retrofit as well. Leaking ducts can pull supply air in from a garage that is contaminated with chemical fumes, a yard with pesticides, or an attic with mold or dust.

Heating & Air Conditioning

In hot and humid climates in the U.S., cooling uses 1/3 of all electricity. For electrically heated homes, about 11% of total electricity is used for space heating. For homes heated with natural gas, about 53% of total gas is used for this purpose.

The most cost effective ways to save on heating and cooling energy are to seal your air ducts, apply caulking and weatherstripping, and place solar screens over older windows. However, if you are replacing your unit, get a high-efficiency air conditioner. If you heat with electricity, install a heat pump. If you already have a heat pump, install a higher efficiency unit.

For those who want to get top-of-the-line equipment (which does not always yield a quick payback), consider central units with inverters, minisplit units that cool each room or area of the home without ducts that can leak air, or geothermal heat pumps that use the earth’s temperature to heat and cool.


In the hot and humid Southern U.S., lighting used about 8% of the electricity in the average home.

Light Emitting Diodes (LEDs) can save 80 to 90% of the energy used by incandescent bulbs sold just a few years ago. And saving electricity on light means saving electricity on air conditioning.

However, make sure that the LEDs you buy have a good Color Rendering Index (color quality) of 90 or above. And if you place them in enclosed fixtures or use them with dimmer switches, make sure the LEDS are designed for them. Otherwise, lamp life will be greatly reduced.


Electric cooking uses about 1% of the electricity consumed in a single-fuel home in the hot and humid part of the U.S.

Induction cooking can lower electric use, but only in certain situations. If a cooking vessel does not completely cover a burner, induction cooking can save as much as 46% compared to a strip-heat electric range. But if a cooking vessel completely covers the burner, strip heat can actually be a little more more efficient than induction cooking, because it captures the heat emitted from the burner much better.

Induction strip heating is still expensive if purchased as a range/oven unit. However, single burners can be purchased at much lower prices.


Refrigerators are the most energy-consuming appliance after water heaters. In the hot and humid Southern U.S., they use about 6% of electricity consumption.

Electricity use per unit has fallen 45% since 1990. However, the most efficient unit sold today can save 69% compared to 1990 levels.

Solar Cells

Solar cells can provide most/all of your electricity consumption on an annual basis. However, you should reduce your needs with energy efficiency measures and efficient appliances as much as possible before you self generate.

Solar Water Heating

In hot and humid climates in the U.S., solar thermal water heating can save 70% to 75% of the energy used to create hot water.

A recent innovation is a solar-cell assisted heat pump water heater, which uses direct current electricity to provide resistance heat during daylight hours.


About 1/6 of the electricity used in homes in hot and humid climates in the U.S. is from "plug loads," from niche appliances to electronics. About 1/3 of these plug loads is from TVs and associated home entertainment equipment.

Buying efficient televisions, electronic devices, and computer equipment carrying the Energy Star label is one of the best ways to manage plug-load costs.

Water Heater

In hot and humid climates in the U.S., water heating makes up 14% of consumption in electrically heated homes. For homes with natural gas, about 34% of total gas consumption is used for this purpose.

Quick payback measures include installing low-flow showerheads and aerators, or if you have them, installing better ones. If you have a garage or basement and use electrically heated hot water, consider upgrading to a heat pump water heater, which can save 50% and more compared to standard “strip heat.”

Tankless water heaters also save energy. However, the cost is so high that you will rarely get a quick payback in a residence. These are more appropriate for commercial uses serving large numbers of people such as laundries and restaurants.


New windows for existing homes do save energy. They do several other good things as well, including reducing noise, dust, and sometimes insects. However, if the only reason you are buying a new window is to save energy, and your existing windows have good weatherstripping, then consider solar screens instead. They are much more cost effective.

When considering windows for old or new homes, look for a Solar Heat Gain Coefficient of 0.35 or lower. U-value, the insulation effectiveness in the frames, is also good for comfort. Again, a value of 0.4 or lower is good. However, while U-values are good for comfort, in the Southern U.S., they do not save a lot of energy relative to their cost.

Also important is what the frame is made of. Frames made with vinyl and ABS plastic are derived from toxic chemicals. Wood, fiberglass, and aluminum are much more sustainable (though aluminum has lower U-values).

The Energy Efficient House

About 23 million households in the U.S. are in hot and humid climates like Austin.  Click on the house features to see more info! 


2021 Series on Back-up Generators

Backup Plan Part 1: Unreliable electric system creates rush to backup generators

The massive Texas power outages that took place in February 2021 left many people feeling insecure about reliable utility service. This is the first in a series of five articles about the rapidly increasing number of backup power systems being installed in Austin area residences.

Backup Plan Part 2: How the Texas electric grid broke

This is the second in a series of five articles about the rapidly increasing number of backup power systems being installed in Austin area residences.  This story explores the key motivator of the purchase of backup systems in Texas.  It will provide a concise but detailed explanation of what transpired to cause the state’s massive electric grid collapse in February 2021.

Backup Plan Part 3: Environmental implications of residential generators

This is the third in a series of five articles about the rapidly increasing number of backup power systems being installed in Austin area residences.  This story focuses on the environmental effects caused by onsite generators, including energy use and air pollution.  The results are not black and white.

NEXT Backup Plan Part 4: Did the Legislature fix the Texas electric grid?

This is the fourth in a series of five articles about the rapidly increasing number of backup power systems being installed in Austin area residences.  This story details the shortcomings of attempts by the Texas Legislature to repair the state’s energy system.

Austin Energy’s Clean Energy Programs

  • Every year, a benchmark survey is conducted for electric utilities in the U.S.  In 2017, Austin Energy had the lowest average Residential consumption and bills of any major utility in the Electric Reliability Council of Texas.  This is because of an effort almost 40 years old to make Austin buildings more efficient.  Find out more about energy-efficiency programs for all types of buildings in the articles below.
  • Since 2006, Austin Energy has been a leader in the promotion of clean electric vehicles that reduce oil imports and conserve energy. There were more than 7,400 EVs in Austin in 2019.  Almost 800 charging stations are within 10 miles of the city.  And you can hook up to them for unlimited charging for a small monthly fee.
  • In 2018, Austin Energy derived 38% of its electricity from renewable wind and solar power.  By 2027, the utility plans to obtain 65% of its electric supply from renewables.
  • Austin Energy has made it easy for homes and businesses to purchase even greater shares of renewable electricity.  The GreenChoice® Community Solar programs allows any customer to purchase 100% wind power though a fuel surcharge.  And building owners can receive utility rebates to install rooftop solar panels. 
Read more about how to participate in our internationally recognized clean energy program in the links below.

Residential Conservation Programs

Residential customers can receive rebates and low-interest loans, as well as quality control for installation, for weatherization and efficient air conditioners and heat pumps in 1 to 4-unit dwellings.  Programs also include air conditioner/heat pump rebates, point-of-sale rebates for energy-saving items such as insulation and LEDs, and free weatherization for income-qualified applicants.

Multifamily Programs

The Austin Energy Multifamily Rebate Program provides rebates to install energy-efficiency improvements in multifamily communities. 

Commercial Conservation Programs

Saving energy and money can determine the success or failure of a business.  Commercial energy efficiency rebates and incentives through the Austin Energy Commercial Rebate program help small to large businesses and non-profits maintain a comfortable working environment while saving energy, all at a lower cost. 

Renewable Energy Programs

GreenChoice® offers customers who own or rent the opportunity to choose 100% renewable Texas wind energy.  Austin Energy’s solar incentive program encourages residents to purchase and install solar systems by reducing the upfront cost to go solar.  Thousands of systems in Austin serve various types of customers including residential, commercial, multifamily and nonprofits.  

Austin’s Clean Energy Contractors

The City of Austin began its financial incentive programs for energy efficiency in 1982.  Since 2004, the City has offered incentives to provide home solar power.  To assist ratepayers, the Environmental Directory has created a list of the main conservation and solar energy contractors in the Austin area in 2016.

Electric Vehicles

Austin Energy has been a world leader in electric transportation since 2006 when it first began to promote the technology.  It has set up an ever growing number of charging ports, almost 800 in 2019. And it offers special charging rates, and offers home charging station rebates to enable and promote increasing numbers of Plug-in Electric Vehicles.

2017 Theme Article on Global Warming & Clean Energy

Compass rose with sun rays for directionThe theme of the 2017 Directory was about how to design an electric grid in Texas using only clean energy technologies that exist today, but in the real world.

• The first part, “Natural Gas,” reviews the proposal of Austin’s municipal utility to build a new gas plant to reduce Austin’s carbon-emitting coal plant.  A great deal of criticism has been received on this proposal.  I have tried to follow down arguments and rumors to determine the real facts.

• The second part, “Challenges to Clean Energy,” describes obstacles to running an electric grid totally based on clean energy, including the need for dispatchable power to mitigate the gyrations of intermittent wind and sunlight, the slow-paced development of new technology, and barriers to low- and moderate-income households.

• The third part, “Clean Energy Alternatives,” discusses advanced energy-efficient technologies, renewable energy options for dispatchable power, and Smart Grid techniques and technologies to manage the electric system.

• Finally, there will be a “Map,” with a compass rose to guide strategies towards this long-range goal.

Being right about the dangers of global warming is not enough. Strategy, not stridency, should guide the way forward.


Global Warming and Clean Energy

We cannot tell an idealist marching in a climate rally, motivated by horror as they watch the world melt down, that they have no right to be emotional.  The prospect of global extinction tends to do that to people.  However, emotion (by itself) will do little good. So I decided the theme of the 2017 Directory would be how to design an electric grid in Texas using only clean energy technologies that exist today.

Part 1

Natural Gas, Part 1: Getting Too Popular

Seen in a bubble, natural gas seems an ideal fuel for a new generation of low-emisson, efficient, and affordable power plants.  The real world, however, does not allow such a simple choice. The risks are often national and international in scope. They include competition in with other domestic end uses and international markets, national security, supply limits, and the environment.

Natural Gas, Part 2:  Fracks from Fiction

Oil and gas drilling was never benign; it has become even more invasive with the widespread adoption of “fracking.” This employs high-pressure water, dangerous chemicals, and occasionally explosives, to fracture earth saturated with oil and gas that is accessed through horizontal wells.  Almost half of all domestic oil and over half of all domestic gas in 2015 were extracted by fracking.  Since gas is the most likely conventional fuel that will be used to balance renewable energy intermittency in Texas, its environmental effects need to be considered in detail.

Natural Gas, Part 3:  The New Gas Plant and Race

This article investigates alleged racism in siting a new power plant.  But it goes further and reviews the evolution of Austin’s energy infrastructure over more than 100 years.  Relative to the span of recorded history, providing electric power and natural gas to large numbers of people is a recent innovation.  Read this story and you will view a different side of Austin.  It was a more primitive place, where staying warm in the winter dwarfed concerns people had about air quality and asthma.  

Part 2

Challenges to Clean Energy, Part 1: Intermittency and Renewable Energy

Solar photovoltaics (PVs) and wind are intermittent.  They cannot be turned on and off when needed.  It is instructive to look at how some of the world’s renewable electricity leaders attained a high degree of renewable energy integration.  While there are impressive examples and lessons that have been learned, no country or utility has truly solved the problem.

Challenges to Clean Energy, Part 2: The Limits of Technology

If you read journals and blogs on clean energy, many writers and reporters are smitten by these new technologies and their potential.  However, new technology is not flawless, and just because it exists does not mean it is affordable, appropriate, convenient for everyone, or will be adopted quickly.

Challenges to Clean Energy, Part 3: Effective Ways to Help the Poor

We need to think strategically and choose carefully when deciding on programs to help low- and moderate-income consumers with energy costs. There will never be enough money to provide all the assistance needed. 

Part 3

Clean Energy Alternatives, Part 1.1: Energy Efficiency

Between 1982 and 2016, Austin’s energy-efficiency programs saved about 1,200 Megawatts of peak power (about 31% less than what would have been used if the efficiency programs had not existed). This is likely the main reason why Austin’s Residential electric consumption and bills were the lowest of any major utility in the Electric Reliability Council of Texas in 2017. This article provides a history of what led to the establishment of these programs, and discussion of how Austin can become even more energy efficient.

More Leading Edge Technologies, Part 1.2: Best Products for Homes

Continuing on the idea of leading-edge technologies in the article on The Limits of Technology, this article discusses the best technology and products for Residential cooling and heating, and LEDs.

Clean Energy Alternatives, Part 2:  A Steady Hand: Dispatchable Renewables

Intermittent renewable power from wind and solar PVs will not be able to support a modern electric system that requires electricity to be dispatched on demand.  This article examines 4 clean energy alternatives for Texas: 1) Biogas; 2) Biomass wood pellets; 3) Concentrating Solar Power; and 4) Compressed Air Energy Storage (CAES) coupled with intermittent renewable energy. 

Clean Energy Alternatives, Part 3: The Smart Grid

Energy efficiency goes beyond installing efficient equipment and retrofitting buildings.  It also means modifying the electric system itself to be more efficient with conservation-based rates, smart thermostats, and efficient management of the distribution system.  Energy storage located near buildings is also important for a clean energy grid.  It can save intermittent renewable generation for times when it is most needed while lowering electric bills, particularly for commercial customers.  


A Map for Clean Energy in Austin

Creating a plan for Austin Energy to rely on 100% clean energy is not a simple affair.  Anyone attempting to cajole you that this goal is quick and easy is either misleading you or misleading themselves.  No one person could write such a plan – at least without many years of work.  Instead, this article ends with a summary of steps needed for a transition to clean energy.  These strategies could analogously be labeled a “Map.”

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