Energy costs during off-peak hours are significantly lower than during peak hours. By scheduling energy-consuming devices like your pool filter pump to run during off-peak hours, you can reduce energy costs with no change in performance.

Hot tubs with old, waterlogged or damaged covers, or not covered at all, can result in the loss of immense amounts of heat. The cover holds in heat and prevents excess evaporation, which keeps energy costs low and conserves water. They also prevent children and pets from making it into the hot tub unsupervised.

They can cost-effectively convert sunlight into electricity. A contractor specializing in solar energy can help select the right system for your needs.

Typically, fuel cells have a 40%-60% efficiency (compared with 25% for photovoltaic generators and 30% for coal-generation stations), which can climb to 85% if the exhaust heat is fully utilized. Fuel cells are the most energy-efficient devices for extracting power from fuels. Capable of running on a variety of fuels--including hydrogen, natural gas and biogas--fuel cells can provide clean power for applications ranging from less than a watt to multiple megawatts.

This option supplements solar power with another generation source, such as wind or electricity, and may involve battery backup. Because the peak operating times for wind and solar PV systems occur at different times of the day and year, solar PV-hybrid systems are more flexible.

Wastewater generated from laundry, dishwashing, and bathing, can be recycled for irrigation purposes in a graywater system and can help reduce your water usage by around 50%.

A rainwater cistern will help reduce your demand for utility-supplied water for irrigation, particularly in seasons of unpredictable weather. Get a large, permanently installed cistern and you will be able to store more rainy-season rainfall for use during no-rain periods.

A heat recovery system uses warm drain water to warm pipes that are bringing in fresh, clean water on its way to your water heater, thereby reducing the energy used to heat water.

Induction cooking is considered one of the most efficient cooking technologies, with up to 90% of the energy consumed transferred to the food, compared to about 74% for traditional electric cooktops and 40% for gas.

A leaky toilet can waste 20,000 gallons of water a year. Check for a toilet leak by putting dye or food coloring into the tank; if color appears in the bowl without flushing, there is a leak that should be repaired.