Keeping cool this summer will cost you

Higher electric rates are right up there with mosquitoes, humidity, and rainouts when it comes to the inconveniences of an Iowa summer.

Summer rates begin June 16 for Alliant Energy's Iowa customers and began June 1 for MidAmerican Energy customers.

Alliant's rates for up to 500 kilowatt hours per month go up 19.3 percent in the rate zone that includes Cedar Rapids. For the second increment of power to 700 kilowatt hours, they increase about 40 percent. For the third increment of power up to 1,200 kWh, they increase 172.5 percent.

MidAmerican Energy's rates went up 14 percent for the first 800 kWh of power, and 107 percent for power used above 800 kWh in the rate zone that includes Iowa City.

The summer rate differential is higher for the larger increments of power mainly because electric rates in the non-summer months are in “declining blocks” as power consumption increases.

Utilities are allowed to charge more for power in the summer months because that is when demand peaks due to the use of air conditioning. At peak demand periods, utilities often activate power plants that are more expensive to operate, or buy power off the grid at much higher rates than their own cost of production.

The good news for utility customers is that the power crunches that have led to voluntary service interruptions and even brownouts in some past years don't appear to be much of a threat this year.

Industrial power demand from Alliant Energy has been  reduced by the recession, Alliant Energy spokesman Ryan Stensland said, as manufacturers have closed some plants and cut back at others. That doesn't mean there can't be power interruptions, however. The utility has also added internal generating capacity at its new Whispering Willow wind farm.

Stensland said power shortages can result from transmission difficulties on the power grid, which make it difficult to move large amounts of electric power from one area to another. They can also result from unexpected power plant problems that limit production.

MidAmerican Energy looks for this summer to be about like the summer of 2009 in terms of supply reliability, spokeswoman Ann Thelen  said. That would be good news, since interruptions were low last summer.

Keeping the power on and the bills reasonable this summer will in a sense go hand in hand, since reducing power use also reduces the likelihood of outages.

The following tips for reducing summer electric demand come from the Iowa Energy Center:

• Close windows and doors during the hottest part of the day. If the house is well insulated and has few air leaks, the inside rooms should stay relatively cool in the afternoon.
• Open windows on cool nights with low humidity, using fans or natural breezes to flush out the heat inside your home.
• If one side of your house is cooler because of shade, use fans to blow air to the hotter side.
• Leave windows closed when the humidity is high both in the daytime and at night. Your air conditioner will have to work extra hard to remove excess humidity before it can begin to cool it.
• Keep interior lights dimmed or turned off during daylight hours to reduce heat gain from light fixtures.
• Shut down your computer if you won't be using it for several hours.
• Construct a sun shade over a concrete patio. A concrete slab reflects sunlight and radiating heat into your house.
• Place a shading structure over the compressor (outdoor portion) of your air conditioner to help it operate more efficiently.
• Use an exhaust fan when you take long baths and steamy showers to reduce the humidity it will cause in your house. Be sure to turn off the exhaust fan afterwards, or it will pull the cool air out of your home.