Monkeying around with DIY solar.

SOPRAY exhibitor Gina


Ever since setting up the off grid solar system at Three Dams Estate, I've been pretty obsessed with the potential of solar PV to create free energy from the sun. Earlier this year being the renewable nerd that I am, I attended a Solar and Renewable Energy trade show here in Melbourne and was able to acquire some solar panels from the Chinese Sopray exhibitor. Gina on the stand said it was too expensive to ship the panels back to China and offered to sell me the 4 panels (250, 260, 295, 140 watt) for 0.60c per watt ($600).

I didn't have an intended purpose for the new panels but had seen those cheap "plug and play" grid tie inverters on EBay and wondered if I could try and set up a small PV set up on the house we rent here in Melbourne. In researching the feasibility of this, there was some doubt if theses small inverters would actually work with the new digital smart meters we have here in Melbourne now and whether in fact the power generated by the panels would actually be measured as a "load" and subsequently billed as "usage". I decided to give it a try and purchased 2 x 350 watt inverters on EBay for about $80 each.

The next step was to construct a simple array frame to secure the panels to the rear patio roof and run the cabling in through the laundry window and connected to the back of the inverters. I needed up using a separator inverter for each panel as the panels were different (polychrystalline and monochrystalline) and of different power ratings. With identical panels one 600watt inverter would have done the trick.

The panels have been up for 2 months now and as we are coming through Spring with more decent sunlight, the results so far are very encouraging. On a good sunny day between the hours of  about 9am and 4pm the panels generate enough power to put our power consumption at neutral (see graph below). I'd highly recommend this time of basic install to anyone with a bit of DIY nouse. The whole set up cost no more than around $600. Feel free to contact me if you have any queries.

Frugality is the key!

The great thing about having a part time off grid house is that it teaches you a lot about energy conservation. When you have a finite supply of daily power that is dependent on the sun shining and the wind blowing, you learn to be pretty frugal with your energy usage. It's easy to waste energy when you're connected to the gridpower supply is infinite. Learning to live off the grid is pretty easy once you get the hang of it and anyone who has spent time up here in Heathcote knows that we don't really do anything that differently here than we do at our place in Melbourne.
In the 6yrs that we've been off grid here, we've discovered a lot of tricks to conserve power and put them into practice in our Melbourne home and have managed to bring our monthly consumption down to about 3.5 kWh per day (the average is 18-20 kWh).

Here are a few ideas that will help bring your energy bills down.

1. Lighting.
Replacing old globes with LED globes is the first step. These can be sourced as cheap as chips on EBay. I recently replaced 12 50 watt halogen down lights at my Mum's house with 12 watt LED globes. Instant power reduction from 600 watts down to 144 watts. It goes without saying that turn off lights in rooms that aren't being used. Porch lights don't need to on unless you're expecting someone to call.

2. Heating.
Only heat the areas you are using. Consider closing the openings to rooms without doors by hanging heavy curtains to contain the heat. Put on a jumper. For gas heating, close (and cover) vents in rooms that aren't being used.

3. Put a timer on your chest freezer.
The chest freezer does not need to come run throughout the night. Consider putting a cheap $10 timer on the power plug that switches off the power to it from say 9pm until 6am. During the winter months this is a great energy saving trick as a freezer will retain its temperature throughout the night if it's unopened.

4. Check you seals

While we're on freezers, make sure the door seal in the fridge and freezer is in good nick and seals well. A damaged seal will mean the fridge will come on more often and for longer as valuable coldness is escaping.

5. Use a thermos.
If you're a big tea drinker, consider boiling the kettle ONCE and fill a thermos to use throughout the day rather than boil the kettle each time.

6. Switch off!

All unused appliances switched on at the wall draw small amounts of power.
This includes phone chargers and anything with a transformer power pack. Standby power usage can add up over the course of a year.

7. Standby mode.
Despite what they tell you, LED TV's are power hungry. The bigger the TV, the hungrier they are. If you're not watching it, TURN IT OFF!

8. Use your electricity to boil water rather than the gas.

With the price of gas about to explode, it's often cheaper (and quicker) to boil water for cooking using the kettle first and then transfer it into the saucepan on the gas stove.

Here comes the Spring!

Arrived here for the first time in a month to a perfectly still, serene Spring afternoon. Very excited to see that after 4 yrs, the Silver Princess in the turnaround has finally flowered! The fruit trees are also flowering so the weather has definitely turned although 2 deg expected overnight so Tarkyn got onto getting the fire going (It's funny how you can always record the first fire of the season but you never know when the last will be!)

Things to do this weekend:

Solar array upgrade to add another 140watt panel facing West. 

Espalier the apple tree. 

Prepare vege beds for spring planting. 

Relax on the deck with pizzas and wine.

Will be time to get back in the pool in a few weeks!