Measuring Matters

We're all about using renewable energy, and we want to provide the tools to help people find systems that suit their energy needs. But if you only know that you use "a lot" of energy, you will discover only that it will cost you "a lot" to make it with sunshine. If you want to reduce your home's energy use and also formulate a plan for an RE system, you will need to get specific about what is using all that energy. Sometimes that's easier said than done.

Your utility bill will show how many total kilowatt-hours (kWh) per month your entire household uses, but that won't really show you where to make your improvements. So how do you get accurate numbers for individual loads? An inexpensive meter such as the Watts Up? or Kill A Watt can measure 120 VAC plug-in loads, but what about hardwired loads and 240 VAC loads? In some cases, you can look at the nameplate to find the appliance's power rating (in watts), and multiply by hours of use. In other situations, it's harder, especially with cycling loads such as clothes dryers, water heaters, and heat pumps. That's where hardwired utility-style kilowatt-hour meters can come in handy.

Recently, the energy club in my neck of the woods installed five inexpensive, refurbished utility-style kWh meters on one conventional, electric-tank water heater and four electric backup heaters connected to solar hot water systems. So far, we're seeing roughly 10 kWh consumed per day by the conventional heater, and half of that or less consumed by the SHW backup heaters.

We're also going to monitor two heat pumps and their backup heaters. Manufacturers claim that heat pumps are two to five times more efficient than other electrical heating sources. But it's difficult to find real-world numbers from actual homes, since heat pumps are rarely monitored separately from the rest of the house.

Measuring the energy use of specific appliances helps us be smarter about how we use energy, and helps us make better renewable energy decisions. Over the next few years, we hope to have some hard data to share, and we hope our research will help existing and future RE users.

Maybe someday monitoring technology will be incorporated into every home design, making it easy for homeowners to understand how much energy each appliance is using—and better yet, how much each is wasting.

—Ian Woofenden for the Home Power crew

Think About It...

"We can create a more sustainable, cleaner and safer world by making wiser energy choices."

—Robert Alan, American writer, artist, social activist

Getting Started With Solar

Getting Started With Solar

Do we really want the one thing that gives us its resources unconditionally to suffer even more than it is suffering now? Nature, is a part of our being from the earliest human days. We respect Nature and it gives us its bounty, but in the recent past greedy money hungry corporations have made us all so destructive, so wasteful.

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