PG&E energy alerts can help you know when it's time to pull back on your energy use to save money.

It’s useful to know how to save energy, but it’s especially useful to know exactly when your energy consumption is starting to cost you more money, so you can take action. Customers of the Northern California utility Pacific Gas & Electric now can sign up to receive e-mail messages alerting them when they’re crossing into a more expensive billing tier.

Opt-in “tiered alerts” are available to the more than 7 million PG&E customers who have smart meters installed. To sign up, visit pge.com/energyalerts/

How does this service work? PG&E explained it in an e-mail…

According to PG&E:

“The State of California has adopted a policy to encourage energy conservation where utilities like PG&E charge residential customers on a tiered rate structure. Each month, all customers start at Tier 1 where energy costs the least. But as you use more electricity, you go from Tier 1 to Tier 2, and can go all the way up to Tier 5. The higher the tier, the more you’re paying for a kilowatt hour of electricity.”

I received a PG&E tier alert for some older relatives, whom I assist in managing their energy costs. In their case, the alert was for going from Tier 2 to Tier 3 of consumption. It noted: “Based on the pace of your electric use, you are projected to cross into Tier 5 by the end of the billing period.”

I think I’ll be able to use this information to help my relatives manage a few things at home to avoid hitting Tier 5, the most expensive tier. PG&E describes how energy alerts can help consumers monitor and control their energy costs.

I applaud PG&E for this service. As part of it, PG&E allows customers to log on to the PG&E web site to see an estimate (updated daily) of their electric use and costs to date. Based on the research literature on energy feedback, this type of information — together with other services, such as more frequent and more detailed data — can yield energy savings of 15%.

Speaking of feedback, I’ve told PG&E that this alert service is great. However, it would help to know exactly what it means, pricewise, to change tiers.

Here’s how PG&E’s tiered residential electric rates work in this case:

• Tier 2: 14¢ per kWh
• Tier 3: 29¢ per kWh
• Tier 5: 40¢ per kWh

I’d also love to have those month-to-date energy use and cost reports e-mailed to me, so I wouldn’t have to remember to log on to see them.