Walgreens To Build First Self-Powered Retail Store 186
MojoKid writes "We hear about green deployment practices all the time, but it's often surrounding facilities such as data centers rather than retail stores. However, Walgreens is determined to go as green as possible, and to that end, the company announced plans for the first net zero energy retail store. The store is slated to be built at the corner of Chicago Avenue and Keeney Street in Evanston, Illinois, where an existing Walgreens is currently being demolished. The technologies Walgreens is plotting to implement in this new super-green store will include solar panels and wind turbines to generate power; geothermal technology for heat; and efficient energy consumption with LED lighting, daylight harvesting, and 'ultra-high-efficiency' refrigeration."
Re:Geothermal heating? (Score:5, Informative)
Re:Kilowatts? (Score:2, Informative)
Re:Kilowatts? (Score:4, Informative)
You've got it backward, I'm afraid. Watts are a measure of power, while watt-hours are a measure of energy (power times time.) A device that uses one kW of power while operating uses 24 kWh of energy per day of operation
Re:Kilowatts? (Score:5, Informative)
A watt is calculated by volts (a measurement of electrical potential) time amps (a measurement of resistance). Notice that there is no time value in that calculation.
To correct your calculation;
a 1 kilowatt device used constantly for 24 hours uses 24 kilowatt hours. Notice watts time hours equals watt hours. The kilo is there just to reduce the number of zeros needed. for example a 1 watt device used for one thousand hours uses 1000 watt hours or 1 kilowatt hour.
Re:Lighting Choices Are Not Extraordinary (Score:3, Informative)
I picked lighting because it was the most-obvious waste of words in the article for the sake of green spin.
The "geothermal" mentioned in TFS (who reads articles, really?) is likely a ground source heat pump rather than a subterranean heat source/sink.
I like the efficiency numbers of such heat pumps, but am concerned about diminishing returns over time in areas with unbalanced heating and cooling seasons.
Evanston, IL is close to Chicago - 6450 HDD65, 750 CDD65 .
Assuming the target temperature is 65F (although 70-75 is more realistic in the US) and ignoring heat generation within the space (minimized by using "green" electronics and lighting), the pump could be pulling heat from the ground about 8 times as often as it puts heat into the ground.
This would tend to cool that ground over time, barring external influences.
The well field in what should be a heat source will be warmer than the ambient air on cool days at first, then on cold days after a few cycles, then only on the coldest days.
Once that has happened, they may as well have chosen an air-source heat pump (current models meet their design heat output to around 4F without significant efficiency loss) and foregone the cost of wells.
"Ultra-high efficiency refrigeration" sounds pretty cool.
I was under the impression that regulation of refrigerants to minimize ozone depletion (while in turn increasing global warming potential, but that's a different conversation) led to refrigerant cocktails operating at higher pressures so that their cycles would be useful in temperature ranges suitable for cooling food.
Do they have air-source heat inverters with food coolers as a source and HVAC as a sink?
I almost want to read TFA...
Re:But... (Score:4, Informative)