Case Study: Classic 4 x 2 family home
EXISTING SET UP
Classic 4×2 family home in metro Perth with a family of 4. The family wanted to make a dent on their electricity bill that peaked in the summer months to $900 for a 2 month period. Whilst at the home it was noted that there were numerous light fixtures that had incandescent globes and a ducted reverse cycle air-conditioning system.
As no previous solar system had been installed there was roof space room for the max array to feed a 5kw inverter.
The existing 48 incandescent light fittings had a total full load of 2010 watts. Over a year the total usage and cost was 3712.50 KWH @ $0.25752/kwh = $956.04 per year.
The ducted reverse cycle air-conditioning unit was rated at 14 kw of cooling. The unit was gassed with R410A refrigerant and it’s estimated the system would cost around $1287.60 per year to run.
We were able to offer the client a renewable energy solution which included solar panels, eco lighting and re-gassing the air conditioning unit. Giving the family the opportunity to significantly reduce their current usage.
The roof had good orientation and room for 6.4kw array and 5 kw inverter to produce an average of 29 kwh of power per day across the year. Without metering the home over a typical one week period it is difficult to determine their usage at different times to determine how much power would be feeding back to the grid. A conservative estimate would be that they would gain $400 back on to their bill over the period of 1 year. The conservative saving on what the client would use of their produced energy from the solar would give them a further average saving of $1104.66 on their current bill. The total minimum saving by installing a solar system is $1504.66.
By changing the current incandescent lighting to LED fixtures we reduced the total load from 2010 watts to 598.41 watts. Reducing the usage by 2754.8 kwh which equates to a saving of $709.41 per year.
The last thing to do is to safely extract the existing R410A refrigerant from the air-conditioning system and refill it with a hydrocarbon replacement. Changing the gas not only dramatically reduces wear and tear on the system but the immediate effect is a 35% energy consumption reduction on the system. In this instance it equates to a saving of a further $450.66 per year.
We were able to save the family $2664.73 per year.
The fortnightly repayments on the renewable energy solution would be $146.48 based on 36 month finance option or $94.57 on 60 month.