Taking a home, building, community, region or nation towards 100% renewable

Mr PragSust has been doing stuff in renewable energy off and on for several decades. There's a lot of interest in Australian communities in moving towards 100% renewable.  PragSust HQ has been carbon free for some time with a biomass heater, PV's and solar hot water. And we've reduced our energy use through various energy efficiency measures. Generally speaking, reducing your energy consumption, using Green Power and installing renewables such as solar hot water and photovoltaics will reduce your emissions. But if you would like to be a bit more systematic, here's a list of steps that might be useful as an initial checklist at a number of scales.

a/ Characterise the energy use at the site in question. As the old saw has it, if you can't measure it you can't manage it.

• How much energy is used.

• When is the energy consumed within a day, in a week and across the year.

• What sort of energy ie thermal or electricity. 

• How much does the energy cost.

b/ Identify energy efficiency measures. As per the perky little aphorism from several decades ago, "Weatherise before you solarise." In Melbourne, companies such as ecoMaster and ecomad specialise in these assessments for residential and commercial buildings. PragSust HQ has had help from both companies with pleasing results. Specialist companies are available to do thorough assessments for industrial and large commercial sites.

c/ Reduce energy use by implementing cost-effective energy efficiency measures. It's a lot easier to find a cheap, cost-effective, practical renewable solution for smaller energy demands. Australian houses, for example, are generally appallingly inefficient with respect to thermal performance ie they leak heat like a sieve. Heat goes out in winter and comes in during summer. There's nothing sexy about roof, wall and underfloor insulation but it is very effective if good quality and properly installed. Weatherproofing to reduce draughts is simple and effective if done properly. In Australia's generally mild climate a well-designed, well-built house achieving HERS 9+ stars or PassivHaus (Australian Passive House Association and Passivhaus Australia have local introductory information on the PassivHaus approach) should need little to no heating and perhaps a small amount of air-conditioning in hot weather. Other measures such as LED's and energy efficient appliances are nice and easy. For larger industrial and commercial energy users, energy efficiency companies say it's not uncommon for them to find 30% reductions in energy consumption at these sites with quick payback periods.

d/ Determine the residual energy demand.

e/ Characterise renewable energy available at the site including any seasonal variations. Renewable energy sources available might be biomass, solar, wind and so on. Each of these sources will have scales and technologies that suit particular demands.

f/ Cost-effectively match the energy sources available with the demands.

• Is storage cost-effective? This might be thermal storage in a tank, battery storage for PV's or hydro storage at larger scale. 

• Can excess generation be sold? For example, feedin tariffs for excess PV generation beyond onsite consumption. Anther example is industrial parks like the one in Gussing, Austria to use process steam from a biomass CHP system.

• Can any demand be deferred or scheduled to match with generation from an intermittent energy source such as solar?

g/ Have the renewable system installed by a reputable company that will do a good job. PragSust has had excellent results from Corospark for various residential-scale renewable systems. Corospark are also doing PV installations at 100kW scale for commercial sites, energy efficient lighting refits for residential and larger sites and voltage optimisation systems for large energy users. Going Solar are designing and installing solar hot water systems for larger sites including school campuses and apartment buildings.

h/ Identify how to meet the demand remaining after deploying cost-effective renewables.This might be from a Green Power scheme.

Rinse and repeat!

Becoming more sustainable: things you can do around the house

There are lots of ways to be sustainable around the house and many save you money too.  Here are some of the sustainable features and practices at our place

Energy
1.  Rooftop PV panels
2.  Solar hot water system
3.  Insulation installed in roof
4.  Insulation installed in sub-floor
5.  Home heating unit replaced with efficient wood heater. Waste wood collected from local arborist is used to heat the house. Wood ash saved and used on the garden.
6.  Signed up for 100% Green Electricity with energy supplier for the residual electricity used after what we generate
7.  Signed up for 100% Green Gas with energy supplier. The Green Gas scheme uses offsets from voluntary carbon emission reduction programs but at the very least sends a message
8.  Replaced incandescent globes with compact fluorescent and led lights
9.  Switch off appliances at the wall when not in use
10. Hills hoist "solar clothes dryer". During winter we also dry clothes on a rack in front of the wood heater. We do have a dryer that we use occasionally but we're on Green Power so no emissions.

11. No air conditioner. Close blinds when hot, installed flyscreens on all window so they can be opened up to let house cool
12. House is painted a light colour, absorbs less heat
13. Single car household
14. Walk and take public transport in general

 Water
1.  Installed two 9300 litre water tanks

2.  Grey water from laundry used to water garden. Landfax Labs recommended detergent is used so wash water is safe for garden use.
3.  Mulch garden to prevent moisture loss. The mulch is sourced from local arborist waste so this reduces landfill
4.  Water from shower and kitchen sink saved to water garden during periods of minimal or no rainfall
5.  Front loading washing machine purchased when the old machine died. This reduced water/load from around 200 litres  to 50 litres  

General
1.  Grow organic fruit and vegetables
2.  Planted 43 fruit trees, 8 fruiting shrubs (e.g. guavas etc), 7 kinds of berries (raspberries, boysenberries etc)
3.  Buy organic foods
4.  Make our own honey, jam, marmalade, preserved fruit, bread, beer, vinegar and soap

5.  Cook from scratch - e.g. making our own muesli, trying not to buy much in the way of processed foods
6.  Composting system consisting of 5 large compost bins. Collect on average 8 litres of compost each day from workplace to add to our bins, in addition to the compost generated at home. Also use large barrels  (ex-pickle barrels) to kill persistent grasses (which would survive composting) by submersion  and produce liquid manure
7.  Reduce waste, try not to buy overly packaged food and other goods
8.  Happy to buy second-hand stuff and repair existing things, thus reducing embodied energy
9.  Use environmentally friendly washing products
10. Tools such as chain-saw, lawn mower are electric (household is on green power) rather than petrol engined
11. Buy in bulk to save money and trips
12. Always have a pile of re-useable shopping bags in the car, and one in the handbag

13. Thinking twice about what we want and if we really need it, saving up for stuff that really lasts, instead of cheap things that won't
14. Knitting jumpers, socks and other items of clothing for ourselves, family and friends
15. Using a sewing machine to repair and alter clothes
16. Displaying a "No Junk Mail" sticker on the letter box. This saves us around 40 kg of junk mail each year.

Reuse and Recycle  
1.  Store food, lunches in reusable containers - no need to use gladwrap!
2.  Asking our friends to save glass jars and beer bottles for use when we harvest honey, make preserves and home-brew
3.  Saving Moccona coffee jars - they make excellent jars for storing dried foods and spices

4.  Save newspapers and cardboard for use to suppress weeds under mulched paths and in creating no-dig garden beds
5.  Buying goods in second-hand stores, and checking ebay to find pre-loved furniture, clothes and other items
6.  De-cluttering and donating things we no longer use
7.  Bartering goods (eg produce, home-brew, preserves and honey) with neighbours and friends


None of the above things are rocket science and most are super easy to do. In fact, you're probably doing a lot of these things already!