Miscellaneous Topics

Solar Power

How much would it cost to use solar panels to generate the 500kWh a month that I'm currently paying my electric company for?   Niccoli, Nov. 2003

[Update, Feb. 2007: I'm leaving the original answer from 2003 below, but readers should know that in the intervening years solar has finally become affordable.]

Solar panels are still too costly to be a competitive alternative to the grid in most cases. A 116-watt panel goes for about $500. Using the industry standard estimate of five hours a day of full sun, that's 580 watt-hours a day, or 17.4kWh a month. Since you need 500kWh a month, you'd need 29 of these panels. That would cost you nearly $15,000. What you'd save would be about $40/mo. or $480/yr, if you were paying the national average of $0.08/kWh for 500kWh a month.

If we had only the cost of the panels alone, it would take 31 years to recoup your investment, but there are two other problems: First, solar panels are only expected to last around 20 years. Second, we haven't included the costs of storage batteries, an inverter, installation, and maintenance.

But there are some things that could make solar more affordable. First, if you're in a state where electric costs are high (such as California), your system will pay for itself much sooner. Second, there's a good chance that energy prices for will surge by the end of the decade no matter where you live, and that could make solar cheaper when amortized over 15 years or so. Third, many governments (including the State of California) offer generous rebates and tax credits for installing a solar system, which can greatly decrease the cost. If you're interested in going solar, check out Solar Depot, e-Marine, or Gaiam.

Television Sets

Do large screen rear projection TVs consume more electricity than smaller regular ones? -- Susan Hunt-Wulcowicz, Oct. 2004

Why wouldn't you just look at the label on the back of the TV's in question (or check the specs if you're shopping online)? The back of my ancient 19" Samsung TV says 77 watts (though it measures out at 50 watts), and a Sony 51'' CRT projection TV that I found in 60 seconds on Google is listed as 260 watts. LCD and DLP projection TV's should use less -- again, just look an the label or check the specs if you're shopping online.

International Issues

I live in Australia and have bought an appliance from America that is 250 volts. In Australia we use maximum 240 volts. Can I still use the device without adjusting the voltage or will the extra 10 volts problems? The device is the power cord for an Microsoft Xbox and unfortunately their was no manual with it. -- Brett Hogan, Oct. 2004

A power cord is not a device, and it doesn't consume electricity. It simply carries electricity to a device. The 250V designation just means that it's got an international plug, not U.S.-style plug. Assuming that one end fits into the wall and another end fits into your XBox then it's the right cord. Now, whether your XBox is designed to work with Australian current, that I don't know. Check the label.

I note that in the US you have a 110-120 volt system whereas ours in Britain is 220-240 volts. Does this have any bearing on how much power identical appliances use in the two countries?  James de Beresford, Nov. 2002

Good question. Despite the difference voltage, energy use is the same. You use more volts, but you also use less amps, so it evens out. For example, in the U.S. a device might use 120 volts x 2 amps = 240 watts. In Britain, that same device would use 240 volts x 1 amp = 240 watts. So energy use is the same.

And of course, costs are the same, because you're charged by the kilowatt-hour, not by voltage. (Well, the costs won't be exactly the same, because there's a different price for electricity in Britain....)

I'm traveling outside the country. Do I need adapters to plug my appliances in there, and if so, what kind?

Hey buddy, this page is for questions about saving electricity. :) Anyway, this isn't my area of expertise, but I was able to dig up some good resources on the subject:

• Guide to using appliances overseas
• Electricity type by country (voltage, frequency, and plug style)