Post tagged with "heat"


Hot and heavy energy usage: How the demand and price for electricity skyrocketed on a 100° day

  • By Barry Fischer
  • September 5, 2012

The passage of Labor Day sadly marks the end of backyard BBQs and pool parties, but for many people it may also come as a relief: a brutally hot summer is finally coming to an end.

The first half of the year was the hottest ever recorded in the contiguous US. July 2012 became the hottest July on record. And in communities across the country, more than 27,000 daily high-temperature records have been broken or tied so far this year.

Across the river from Opower headquarters, Washington DC faced 11 consecutive days that hit or exceeded 95 degrees…it was the city’s most intense heat wave in 141 years of keeping temperature records.

Thankfully, air conditioners keep us cool and comfortable during these sizzling summer days. More than 60% of US households now have central air conditioning, up from 23% in the late 1970s. But the luxury of A/C comes at an obvious cost: higher electricity consumption.  Exactly how much higher? We found that the average home’s electricity usage on a 103°-high summer day is up to 40% higher than during a typical summer day.

How do we know? We cracked open our data warehouse to examine anonymized energy usage data across 18,000 homes from 3 different cities in the western part of US, which has faced blistering temperatures this summer.  In particular, we explored a few key questions about energy consumption on hot days:

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When the blackout hit, I blacked out my windows and was 33% more comfortable

  • By Barry Fischer
  • July 2, 2012

Like 2 million other electricity customers in the mid-Atlantic region this past weekend, I lost power.

A weekend with 100-degree temperatures is not the best time to be without air-conditioning. But, it got me thinking…is it possible to keep our homes cool in the absence of electricity?

Then it hit me: Don’t let the sun shine into the house. Close the blinds.

Indeed, simply closing window blinds or drapes can reduce solar heat gain into the house by 33-45%. So then, isn’t it a good idea on all hot summer days to close the window blinds when we leave a room for a while?

Yes–I’m going to do it more often. Less electricity needed for A/C use + increased comfort = Nice.

And if you are especially ambitious about blocking out the sun on hot days, you can consider strategically planting a tree to shade your most sun-exposed windows. Field studies conducted in Sacramento have found that “shade trees” can reduce cooling costs by 30% and overall summertime electricity costs by more than 5%.

The only catch: the shade tree needs to remain standing after storms…

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