Living with solar – how make it all work

by Collyn Rivers - Updated 2020

Minimise energy usage first. You can often slash such usage by half - or even more. This requires you to pay for some changes. Doing this, however, and the cost of solar you need is hugely reduced.

Our first (home) all solar house north of Broome (WA), gave invaluable experience. It's up to 17 kWh/day adequately coped with our under 8 kWh/day usage. Building and living with it for 10 years showed that feasible.

Our all-solar 10-acre property on the Indian Ocean north of Broome, Western Australia. Pic: rvbooks.com.au

Our major living with solar achievement, however, relates to moving to Sydney. We bought a solidly-built and relatively new house overlooking Pittwater, that was 100% grid supplied. Planning to install solar, we found previous electricity draw was 31 kWh/day. In this and similar situations, do nothing initially solar-wise

We first tracked down and slashed this high usage. An instant-boiling (and ice-cold) water unit used only a few times day drew over 5 kWh hours each day. Six heated towel rails used 3 kW/h a day. Over 80 halogen lights drew 50 watts each. These were replaced by five and seven watts LEDs (that gave much the same light. A 20-year old fridge drew 7 kWh/day was replaced by one that draws 2 kWh/day. The garden lighting was all incandescent (drawing 1.5 kWh each night) was replaced by LEDs that draw only 150 Wh a night.

An extraordinary find was an old electric door-bell. Despite being used only a few times a week (for a second or two each time) the 230-volt transformer driving it drew a constant 40 watts (almost 1 kWh/day). We replaced it by an old-fashioned manual brass bell.

Within a month we slashed usage to 10 kWh/day, then to 7 kWh/day two months later. It cost well under $5000 to do so. Only then did we install grid-connect solar (initially a 2.4 kW system). Without those initial changes, generating over 30 kWh of solar a day was totally non-affordable.

Usage now (2020) is about 11 kWh/day in winter and a mere 4 kWh/day in summer. Our now 6.6 kW solar input hugely exceeds that most of the time. We initially used the grid network as a 'virtual battery'. Since then we have added a 14 kWh Tesla battery and hardly ever draw grid power. In summer we export 30 kW/h a day at a two-year contracted 20 cents per kWh. Our electricity bills rarely exceed the fixed service charge. Mostly, the supplier pays us.

How to slash usage - change usage habits

Turn off all appliances at their wall sockets, never by a remote control alone. This particularly applies to anything made prior to 2014 that has a small power unit built into its plug. It applies also to many electrical appliances bought (or via eBay) from overseas. Unless turned off at the wall switch, each little power unit continues to draw power. Such power varies from a watt or so - to as high as 10 watts. While each may seem trivial, the average home has up 30 or so of these. At even 3 watts each, that's over 2 kWh/day.

Do not leave lights on unnecessarily. Do not leave an un-watched TV with its sound turned down. Turn it off (at the wall!). Use less water when showering. Buy only energy-efficient appliances.

Do not use an instant boiling/cooling water system. Boiling water takes only a minute or two in an electric jug. Have a cooled jug of water in the fridge.

How to slash usage - items to change

Consider selling any fridge made prior to 2014. Replace by one that has a high Energy Star rating. Never have two or more smaller fridges. Have just one of similar overall capacity. A  (say) 750-litre fridge draws about half the power of three (each of 250 litres) fridges. This is because the single large one has far less surface area.

Change all lighting to LED. This is readily done as LEDs are now made to fit existing fittings. Do not buy cheap LEDs. These produce less light per watt than the more costly ones. They also have a much shorter life.

Living with solar - how much do I need

Right now, grid connect solar works best for those working from home. That which comes in during the day is used that day. Some install batteries to feed the home at night. You are unlikely to gain financially by doing so, but it ensures you still have 230 volts during power outages.

Living with solar - maintenance

Solar does not usually require maintenance. The modules may need occasional cleaning in some outback areas. This is particularly so after a long dusty outback summer. Dry winds cause static charges that attract dust. Brief light rain may not, however, wash it off. It may turn the dust into mud that subsequently dries hard.

Fix dust and static issues by washing the modules with water and detergent. Then rinse with a full bucket of clean water to which you have added just one teaspoon of detergent (it has anti-static properties). Use a squeegy to remove surface water - and then let the modules dry naturally.

Never wipe dry solar modules -  let alone polish them. Doing either or both generates dust-attracting static charges. Static build-up can be reduced by earthing the solar module metal frames.

Apart from the above, solar modules need no maintenance. It is difficult to assess their usable life-span, Some, however, made in the 1980s still produce about 80% of their original output. Total failure is very rare.

Reliability when living with solar

A well designed and installed stand-alone system is usually more reliable than the grid network. Furthermore, the output is cleaner, and the voltage barely varies.

Energy monitoring - an essential

Energy monitoring is essential when living with solar. Many new owners maintain a daily log of energy in and energy out, plus the highest and lowest voltage. Most owners (who have a battery-backed system) eventually settle for daily checking the battery bank's percentage charge. The latter is all that is routinely needed. Anything needing attention causes significant variations.

Easy to install and easy to read. The Xantrex battery monitor. Pic: xantrex.

Solar is not hard to install. Our book Solar Success specifically explains how for homes and properties. Solar That Really Works! does likewise for boats, cabins and RVs. See also the Caravan & Motorhome Book, Caravan & Motorhome Electrics, and the Camper Trailer Book. To know about the author Click on Bio.