New Energy Thinking

Category: Uncategorized

  • What’s up with Hydrogen

    There’s been lots of talk of late about a hydrogen economy.  I’ve looked into this. In a nutshell I can’t see Hydrogen being widely adopted for energy storage within our electricity system. Likewise, I can’t see it being widely used for transport except in some very limited cases.  Its use within the gas network seems like greenwash. However there does seem to be some potential in using hydrogen as an intermediate product in creating transportable liquids like ammonia, methanol and methane for use as export feedstocks or as fuels.

    by Richard Keech

    Published 2018-09-23,  based on investigation done in early 2017

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  • Solar air heating: is it worth it?

    By Richard Keech

    2018-08-14

    Do solar air heaters or coolers live up to their promise?

    At face value the idea of having a device which uses sunlight directly to heat air in winter seems like a good one.  It’s the idea behind a number of products on the market that promise really high-efficiency heating for low cost. We can lump these together in the category ‘solar air heating’.  Solar air heaters sometimes claim thermal efficiencies greatly in excess of that possible with a solar PV panel.

    solar air heating Jane KemeSolar Air heaters (Pic: courtesy of Jane Keme, Melbourne)

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  • Efficiency and Air Displacement

    By Richard Keech

    2018-08-12

    Some systems used for heating and cooling depend on air displacement.  Understanding what this means is valuable, because systems like this are usually inefficient.

    So , what do 1) evaporative air conditioners, 2) fireplaces; and 3) solar air heating systems have in common?  Answer – their normal operation usually requires air displacement.

    Evaporative aircon
    Evaporative cooling and wood fires both involve air displacement

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  • R U o K with insulation?

    If you know a little about insulation then you’ll already know about R values.  However, to really understand insulation you also need to know about U values and K values.

    2018-07-29

    By Richard Keech

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  • Hydronic heat loss in one picture

    by Richard Keech

    2018-07-12

    I thought this picture neatly shows the limitations of passive panel-based heating such as hydronic or column heaters. The thermograph shows most of the heat convecting to the ceiling, allowing much of it to be lost before it can reach the occupants of the room. This is one of the main reasons I never recommend hydronic-panel heating.  In-slab hydronic doesn’t have this problem, but it does have other problems.

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  • Home batteries

    On Wednesday June 27 2018 I spoke to Lighter Footprints, a community group in eastern Melbourne, on home batteries.  Here are the presentation slides.  Here is a video recording of the presentation.

    The presentation references a spreadsheet model for efficient homes with batteries. You can find it here.

  • Renewable electric sunrise

    Yesterday I was enroute to a country client for ecoMaster. I found myself at sunrise driving past the Waubra windfarm at sunrise.  Too beautiful not to stop and take a picture or three.

    By Richard Keech    2018-06-23

    IMG_5076 - Copy

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  • Multi-head splits vs single-split systems

    There’s some debate about whether the best configuration of split systems for multiple rooms is to have multiple single splits or to use multi splits.

    By Richard Keech  2018-06-18

    2015-06-22 10.06.12.jpg
    Multiple single-split systems can be an eye sore

    Introduction

    Increasingly split systems are used to heat and cool entire homes – not just single rooms.  The default way that split systems are deployed is what I call single splits (and sometimes referred to as unitary split systems).  These have one outdoor unit piped to one indoor unit.  And repeat that configuration for each conditioned room.

    The alternative, available from many vendors, is a multi-split. This configuration involves more than one ‘head’ unit inside for each outside unit.  Often a whole home might be served with only one (larger) outdoor unit, and heads in all bedrooms and living spaces. (more…)

  • Is thermal mass over rated?

    Are concrete slabs the best floor for an efficient home?

    By Richard Keech 2018-06-16

    Thermal mass

    Figure 1: Thermal mass is a two-edged sword

    Thermal mass equals efficiency?

    The use of concrete slabs on ground is ubiquitous in contemporary Australian home construction. Conventional wisdom says this is a great thing for energy efficiency because of increased thermal mass.  There’s some truth to this.  However, I think the reality is not quite so simple.

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  • A spreadsheet model for efficient electric homes

    Here’s a way of estimating the benefits of solar, energy efficiency and batteries in a home.

    By Richard Keech, 2018-06-06

    I was commissioned by the developers at The Cape to created a spreadsheet model to help understand the effect of different factors in an efficient electric home.  This lets you ask questions like:

    • How much money can I save by building a home to X stars?
    • Am I better off adding more solar panels or making the home more efficient?
    • What are my likely running costs if I have an X star home with Y kW of PV?
    • Is it worth putting in a battery system?
    • Is it possible to eliminate energy bills entirely

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