How do I sign up for Prime Time Power?
Where can I find information about a home energy audit?
Why doesn't the City of Ames Electric Services offer rebates for efficient air conditioners?
Do I waste energy if I turn my fluorescent lights on and off, or should I keep them on all the time?
Does it cost more to re-cool my home after I turn up my thermostat?
What are degree days?
How would I know how much energy I save if I raise/lower my thermostat at my home?
Who is the Energy Guy?
How do I sign up for Prime time Power?
You can call Utility Customer Service at 515-239-5120, or Steve Wilson at 515-239-5177 for an application, or visit our Prime Time Power page at Prime Time Power.
Where can I find information about a home energy audit?
There is an informative and simple to use home audit program at Home Energy Audit, or call Steve Wilson at 515-239-5177.
Why doesn't the City of Ames Electric Services offer rebates for efficient air conditioners?
In order for an incentive/rebate to be offered, it must be cost effective for the utility. As Electric Services offers one of the lowest electric rates in the Midwest, incentives for reducing energy consumption are difficult to justify. However, Electric Services is currently evaluating this and other types of rebate programs.
Do I waste energy if I turn my fluorescent lights on and off, or should I keep them on all the time?
This is a controversial topic. Whether to turn
fluorescent lights on and off, or leave them on has puzzled most of us as far back as I
can remember. When we used incandescent lighting, this was easy. We always turn out
the lights when we left a room. Incandescent lights are instant resistive loads, and
you use every bit of your bulb wattage (a watt in, a watt out).
It pays to turn off your fluorescent lights. While it is true that the life of a
fluorescent lamp can be shortened a bit if it is turned off and on frequently, the energy
cost savings far outweigh the cost of these lamps and any small additional amount of start
up energy during their lifetime. According to what I read, the balance point is about
10 minutes. The lights should definitely be turned off if nobody will be in the room
for this amount of time or longer.
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Does it cost more to re-cool my home after I turn up my thermostat?
Though it will cost more to re-cool your home after turning up your thermostat, the savings you achieve as your home warms approximately equals this cost. You save during the time your thermostat is at the higher setting. So, you always save when you turn up your thermostat. Certainly, it pays to set your thermostat up at times when your home is unoccupied. When used consistently, a program of setting your thermostat up 5º F can save 15%-20% of your cooling energy and cost for the season.
As an example: In Iowa we run our air conditioners, on average, 600-900 hours per season. A typical 3-ton air conditioner may cost between $300-$700 to operate per cooling season. (This does depend on how cool and dry you like it, how hot and humid it is, whether you are away from the home during the day, etc.). Saving 15% would amount to $45-$105 per season.
Something else you might try. In the morning, preferably around 10:00 a.m. or before, when air conditioning isn't really needed, set your thermostat back a degree or two for a short time in order to cause your air conditioner to come on and dehumidify your home. The dryer air will feel more comfortable, and make your home easier to cool later.
What are degree days?
Degree days are a nationally recognized way of quantifying the need for heating and
cooling. In this part of the country it is based on the assumption that when the
outside temperature is 65° F we don't need any heating or cooling to feel comfortable
inside.
The degree day information is usually used for comparison between two time periods (i.e., this year is warmer compared to last year because we have fewer heating degree days). The term "degree day" is a bit misleading. We are really talking about the difference between 65 degrees Fahrenheit and the average temperature. The heating degree day season runs from July 1 through June 30, and the cooling degree day season runs January 1 through December 31.
The calculation for degree days is the difference between the average temperature for the day, and 65° F. We arrive at the average temperature for the day by adding the highest and lowest recorded temperatures and dividing by two. If the average is higher than 65°F, then the results are cooling degrees because you would have to apply cooling to get to 65°F. The opposite applies to heating degree days.
Example: The high temperature for yesterday was 86°F, and the low was 70°F. We need the average temperature (86+70)/2, which is 78°F. Subtracting 65 from 78 leaves us with 13, and because we would have to add cold air to get from 78 to 65, these are cooling degrees. The high temperature on January 10 was 45°F, and the low was 29°F. The average temperature was 37°F [(45+29)/2]. Because we have to add hot air to get from 37 to 65, we end up with 28 heating degrees.
How would I know how
much energy I save if I raise/lower my thermostat at my home?
This is where we can use degree day information to help us understand energy
savings. We do this by calculating energy used per degree day. The hard part is
allowing for base load (normal electric use without heating, cooling, or unusual one time
events). Generally speaking, base load is the average kWh your home uses during the
"shoulder" months when very little heating or cooling is needed (May &
September). After we have subtracted out our base load, we divide the remaining load by
the degree days for the month.
Example: In 1999, I began using a regular program of setting my thermostat up a few degrees during hot days. How do I know if I saved any energy? I have determined that my base load is 1300 kWh per month. From my bill I found that last June I used 1750 kWh. The year before I used 1775 kWh. Subtracting my base load I estimate that I used 450 kWh for cooling in 1999, and 475 kWh for cooling in 1998. I then divide the kWh by the cooling degree days to get kWh per degree day. In 1998 there were 156 cooling degree days in June. That equals 3.0 kWh/degree day. In 1999 there were 161 cooling degree days in June. That equals 2.8 kWh/degree day. Though it appears that June, 1999 was hotter (156 cooling degree days in 1998 Vs June, 1999's 161), I used fewer kWh per degree day during June, 1999. This would lead me to believe that I was about 7% more efficient in 1999. My program of setting my thermostat up a few degrees is saving me energy.
Another way to look at this is to estimate reduction in cooling energy needed. If you turn your thermostat up from 72 to 78, you have made an 8% change. This can be thought of as an 8% decrease in the energy necessary to satisfy the thermostat. A typical residential air conditioner is 2.5 ton (30,000 Btu per hour). This equates to 8.8 kW. Lets say our air conditioner runs around 600 hours per season. 600 hours X 8.8 kW = 5280 kWh X $.07 per kWh = $370 per season to run the A/C. Eight percent of 600 hours is 48 hours less run time due to thermostat set up X 8.8 kW = 422 kWh X $.07 = $30 saved (8%).
The Energy Guy is Steve Wilson, Energy Services Coordinator for the City of Ames Electric Services.