Recently a UCAN member brought to our attention an insert that went out in the most recent SDG&E bill. It’s a flyer promoting summer energy savings and what you can focus on to lower your energy consumption.
Although I love that SDG&E is doing its best to educate customers, the graph included is a bit deceptive. Here’s a scanned image of the graph:
Our member was concerned because it appears customers without air conditioning were paying more for lighting and refrigeration than those with air conditioning. SDG&E has correctly labeled their graph, but using a bar graph to show percentages can be misleading.
So we decided to revamp the graph to clarify their point. Here’s a better way to think of your energy consumption:
SDG&E's original chart makes no statement about the relative energy consumption for the two groups. However, let's assume that both types of residences have the same energy habits. Let's say that for refrigeration, lighting, water heating, laundry, cooking, TV, computing, and misc that both types of homes use 100 KW of electricity. For the homes without A/C, 100 KW is 100% of their energy. But for the homes with A/C, 100 KW is only 67% of their energy - - the other 33% is air conditioning. That means the total energy consumption of the A/C home is about 150 KW. So the homes with A/C are using 50% more energy than those without A/C. This graph gives you an even better snapshot of energy consumption:
Hopefully our new graphs give you a snapshot of your energy usage and inspires some ideas of where to look first for summer energy savings.