Category Archives: Sustainability

Growing about 30% of my own food

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A rough calculation shows that I grew around 30% of the food I ate in the warmer 8 months of the past year. Most of that was from vegetables grown in Summer and then stored one way or another. I am still eating zucchini, tomatoes, eggplant and chilli from before the frosts. Raspberry jam from two weekends ago should last about a year. There is a kilo or more corn in the freezer and I made tomato puree that will do for a few weeks. If I am lucky I might be able to increase this percentage for next year with more garden beds and a better approach to growing corn and capsicum.   What I cannot conveniently grow myself are dairy foods, cooking oil and most grains. So for the next two years I will experiment with:

  • Nut trees/bushes. Hazelnut and walnut seem appropriate for this climate
  • A small amount of grain crop – yet to be determined
  • Starting capsicum seedlings early in the glasshouse and transplanting in October
  • Starting tomatoes from seed and transplanting in November (glasshouse again)
  • Growing more basil and coriander in a mini greenhouse and/or inside
  • Add another 3 sq metres of garden bed for more vegetables
  • Better distribution of plants so that they get more light and are less crowded
  • Plan my corn two per week over 8-12 weeks so I get more over a longer period (and don’t have to pick and freeze)

Slightly exciting to plan this.

Energy update

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Not much really but I used 5.2 MWh of electricity in a year and generated 3.4 MWh from the PV panels. Predicted generation was 2.6 MWh from the supplier so all seems good to me. Getting the electricity usage lower is going to be hard because of an electric oven and running a lot of electrical equipment. Still I think I can get below 5MWh per annum easily and perhaps to 4 if I replace some appliances and/or install some building automation to control some things.

Sunshine is the best heating

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Well into Winter now and the very short days are here. Paradoxically this is the best time for heating the house from sunshine. Walking on the slate with bare feet when it is -4 degrees outside and opening curtains to let the sunshine in is a great pleasure. With sun coming in to nearly 4 metres almost all the floor is warm now. Late afternoon in the sun is t-shirt weather inside while it is 12 or so degrees outside. This is good and happily the double glazing works very well for the sunny days.

I still think there is some further benefit to be gained from increasing insulation in the roof and walls. That looks feasible before the next summer. Add the increased sunlight from removing shadows cast by the existing pergola and it could add 4 kWh of heating and reduce 12 kWh of cooling (heat leakage) to the daily winter heat budget – when I complete these improvements.

With energy costs approaching 15c and 25c for gas and electricity (per kWh) respectively that amounts to over a dollar a day in gas saving. Effectively $150 a year which is significant but secondary to the sheer comfort and joy of being in a warm and sunny place. Compared with 5 years ago, when I needed to have heating of some sort all of June and July all through the day or be quite cold, the difference is remarkable. 21 degrees inside with no heating on compared to 18-19 with heating on – guilt free :).