Electricity Savings Calculations- Based on Actual Bills

Transcription

1 Electricity Savings Calculations- Based on Actual Bills Please note: The accompanying bills are of a household of 4 adults, a single 200L geyser. Household usage patterns: Energy conscious, regular hot water usage patterns. This sample represents an average-small household. Savings may be significantly higher for larger households. The two electricity bills are for the same period (October to January) of 2008 and 2009, respectively. Electricity usage in kwh is actual routine readings and not estimates. (Please see actual bills page 3 and 4). Electricity tariff in the period 2008 and 2009 was 40c/kWh and 58c/kWh (45% increase), respectively. (Current electricity tariff, September 2009, is at 67c/kWh). Even though tariff has increased, this household s 2009 electricity bill is still less than For a more accurate example, please consider calculation based on these two electricity bills below: 19 October 2007 to 16 January 2008 (3 months) Actual electricity usage: kwh 20 October 2008 to 19 January 2009 (3 months) Actual electricity usage: kwh Difference: kwh kwh = 1 245kWh Savings for the 3 month 58c/kWh: kwh x 58c/kWh = R Average savings per 58c/kWh: R / 3 months = R per month Payback current electricity tariff of 74c/kWh: Savings of R /month R / R = 3.5 years* (without considering further increases!) * Calculated payback period do not take into account further tariff increases of 25% to 35% year-on-year. Hence, as further tariff increases are certain, actual payback periods will be significantly shorter. Considering planned tariff increases this payback period is below 3 years. Please see the Return on Investment section. With a system life expectancy is years, savings for you- and for the environment- is truly significant. The above calculations are considered conservative. Savings vary according to usage, and savings experienced would different for every household.

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4 Return on Investment- Including Annual Tariff Hikes The below ROI tables takes into account the planned 25% increase in tariffs, annually for 3 years (from 2010)- at current 2010 rates of R0.74 per kwh. Savings/year based on above actual bills. Year SWH Return on Investment (ROI) Tariff % Increase per year Tariff per kwh Savings per Year Accumulative Savings 1 25% R 0.93 R 4,659 R 4, % R 1.16 R 5,824 R 10, % R 1.45 R 7,280 R 17, % R 1.52 R 7,644 R 25, % R 1.59 R 8,026 R 33, % R 1.67 R 8,428 R 41, % R 1.76 R 8,849 R 50, % R 1.84 R 9,291 R 60, % R 1.94 R 9,756 R 69, % R 2.03 R 10,244 R 80,001 SWH Return On Investment R 90,000 R 80,000 Accumulated Savings R 70,000 R 60,000 R 50,000 R 40,000 R 30,000 R 20,000 R 10,000 R Years Costs are repaid in roughly 3 years, and by year 10, total savings equate to more than R80, ! And will continue to save! Solar water heaters are a great investment for both the environment, as well as your bank account.

5 Environmental Savings- How You re Helping the Environment 1kg of coal can roughly produce 2kWh of power. kwh savings can, therefore, quite accurately estimate the amount of coal saved, and carbon emissions reduced. A single tree absorbs, on average, 15kg s of CO₂ per year. Accumulative Savings For the Environment Year Coal (kg) CO2 (kg) Trees Savings for the Environment Coal Saved (kg) Carbon Dioxide (kg) Units Trees Years Savings for the environment is truly significant. By 10 years, the amount of carbon dioxide emissions reduced is equivalent to more than what 3000 trees could ve absorbed! Conserve Today. Preserve Tomorrow.