Light bulbs are the simplest example of how this kind of 'green investing' works. Hypothetically, say Mr Banks and Mr Green each have R1,000 to save or invest, and each has ten 50 watt lights in his home that could be replaced by more energy-efficient LED globes. Mr Banks leaves his old bulbs in place, putting his R1,000 in a five-year fixed deposit bank account that pays 8% annual interest. Mr Green rather invests his R1,000 in 5.5 watt LEDs to replace those ten older globes.
Five years later, the R1,000 that Mr Banks deposited has grown to R1,490. But Mr Green is now much richer than Mr Banks. He has saved R5,717 on electricity and another R316 on replacement bulbs, since LEDs last much longer. The new globes were such a good investment, it's as if Mr Green had earned nearly a 33% annual interest rate.
Other examples of efficiency investments that pay high returns include solar or heat-pump water heaters, low-flow shower heads and variable-speed pool pumps. Swapping a 1.1kWh pool pump for a variable-speed pump using 300 watt is an investment that can pay a 31% annual return over five years if the old pump needed replacing anyway, and 21% if it did not.
The LED bulb and pool pump examples assume that the lights are used four hours a day and the pool pump eight hours a day, a R1,50 per kWh electricity tariff and 8% tariffs hikes each year. Actual results could be higher or lower, but under all reasonable scenarios, the investment in an energy-efficient pool pump or lighting pays a much better return than a five-year fixed deposit earning 8% interest.
The My Green Home website offers advice on a wide range of investments that save energy and water, while making a home more environmentally friendly. Visitors to www.mygreenhome.org.za will also find a Guide to Globes and a Guide to Solar Water Heaters.
Those who participate in My Green Home stand a chance to win green prizes, including the grand prize - their own green home makeover. Those who submit a photo of themselves and their most effective energy-saving device or action to the website or via Twitter (@mygreenhomesa) by 12pm on Monday, 21 July are eligible for prizes in a random draw, as well as the grand prize.
