just a mo... ppm

So the government has generously donated another £45 million to the Low Carbon Buildings Fund. Isn't that kind?

This largesse amounts to approximately 75p per person in the UK. What will you do with yours? Put it towards a jubilee clip for your solar hot water system? Or maybe a single solar cell for your PV array... well, half a cell maybe. No, hang on - nearer a quarter.

How about popping down to Homebase for a trowel to dig holes in your garden for a ground source heat pump? Shame it won't cover the cost of a JCB, but you know, times are hard.

You can barely buy a loaf of bread with 75p these days. Small change won't tackle climate change, Gordon - isn't it about time you got serious?

Sailing is surely the purest form of travel. Ah, to traverse the world with nought but a bellying sail; to harness the mighty power of nature merely by swigging on a few halyards and waggling a tiller - what more perfect way can there be to get from A to B?! And what more environmentally friendly? Sailing has no carbon emissions! None!

Last week I found myself back skippering a sail training boat I used to spend a lot of time on. She sails superbly (for a gaffer), and I've had great times on her - and found many fantastic friends on board. Yet, on this trip I found myself getting a mite frustrated. The truth is that she's lost her innocence, her simplicity. The poor boat has become encumbered with gadgets, and they all suck power. There is a fridge to keep food cold; a diesel heater to warm us again when we've eaten our ice cream. The gas cooker now has a fancy power-hungry solenoid valve rather than a gas tap, with a control panel with red buttons, flashing leds and dire warnings. The chart table is surrounded with dozens of instruments that beep and flash, dominated by a huge fancy modern chart plotter with an enormous glowing screen. There is a Navtex. A radar. A complicated wind indicator. Two radios. A log. A GPS. Depth sounder. An Inmarsat - a fancy satellite communications system. (It has it's own big computer screen. It was designed to have a printer attached too however, and complained by beeping in a quiet but maddeningly insistent way, until someone caved in and bought the printer to keep it happy. It sits above the chart table - no-one ever uses it).

It's not just the instruments that have bred and multiplied. The way power is used has changed too. A generator has been installed to keep pace with the electricity use - in itself not necessarily a bad thing, as for a given charge to the batteries, a generator will give that power a lot more efficiently (and quieter) than a propulsion engine. However, now that the generator is there, it seems quite the accepted thing these days to switch it on to merely power a toaster in the mornings!

Of course, being skipper, I could be the kill-joy who forbade toast-making (eat cake, I pronounced, for we had plenty of that, and after all, as well as being bad for the planet, it wasn't very friendly to our neighbours in a quiet anchorage to stick a smelly noisy generator on, was it?). I could (and did) switch off the chart plotter and tell the second mate to get the dividers out. ("It's good training for you"). I turned the freezer off the first evening - the food would keep cold enough for a few days, and we could make do with tins on the last day. I could nag the crew - incessantly - to switch off lights when they were finished with them. I could make them up anchor and hoist sail at 4am to catch the outgoing tide from the river, rather than rise at a more salubrious hour, but have to burn diesel to make progress against the flood.

Alas, despite my attempts at economy, the batteries still slowly drained. On the final morning, just a couple of hours from base and a shore connection, I had to admit defeat as the radio died, the gas solenoid beeped mournfully and prevented us from putting on the kettle for a cup of tea, and the lights began to dim. The batteries were empty. There was no option but to turn the evil generator on and pump some CO₂ into the atmosphere.

Is it possible in this day and age to keep sailing pure and simple, and fossil-fuel-free? I think it is. I suppose there are two possible approaches. One is to become a luddite - an approach I personally am all in favour of. When I go sailing I want to sail; I don't want the roar or smell of a diesel engine to accompany me. My own little yacht, Teal, is as simple as I could make her. I chucked out the motor she came with, and found a pair of oars instead. Electrics I kept to the absolute minimum for safety - navigation lights, a handheld VHF radio, and a depth sounder (arguably, even that was a luxury - and for at least half the long voyage I did on her, it didn't work anyway). Teal got me to the Arctic circle and back, burning just a couple of cans of paraffin in the stove and Tilley lamp, and I had more adventures in that boat than you could pack into a entire fleet of Sunsail yoghurt pots in the Med.

But if you must have your gadgets, that is possible too, for the other approach is simply to get the power for them from a more sustainable source than diesel. On a boat, that's pretty easy - there is plenty of sun and wind around, so solar panels and wind turbines work well.

I suppose the narrowboat I live on is kitted out more along those lines. While I'm happy to live a frugal existence while sailing, I do enjoy a few more luxuries in my permanent home - a laptop for example, decent lighting, an inverter to run power tools. I even run an electric propulsion motor from the battery bank on the narrowboat, so I don't burn diesel even when I'm moving her. It does require a big array of solar panels - but it's perfectly practical.

For the average yacht or sail training boat, a compromise is inevitable. I would argue that keeping things simple is to be welcomed on a sail training boat. Part of the experience is to leave the luxuries of modern life behind for a few days. So lob the chart plotter overboard and wear an extra fleece rather than turn the heater on. Banish the freezer too: it's perfectly possible to last a week without frozen food. Just eat more fresh veg rather than lumps of frozen meat from unhappy intensively farmed animals. (Surely in fact that would be a good thing to do anyway?... but don't get me started on that one...)

It has to be (grudgingly) admitted that some gadgets do bring tangible safety benefits. In a world of dense shipping lanes it's mildly foolish not to have the correct radio channel and a radar for poor visibility. Some use of electricity is inevitable - but it should not be hard to reduce power consumption on the boat to a level that could be provided for by a few solar panels.

Would that not be a good thing? The purpose of sail training is, after all, the development of the young people who come along. Taking them out of range of a mobile phone mast, away from their ipods and TVs and convenience food is all well and good in itself - but to substitute an awesome experience of nature at her wildest, while demonstrating respect and care for the environment they have become a part of... well, heck, would that not be even better?

It's squatting balefully in a corner of my kitchen; green and knobbly, plump, pendulous and slightly sinister. I haven't the faintest idea what it is. My first thought was some sort of pumpkin, but now I'm not so sure. I cut it open cautiously last night, but the pale crispy flesh didn't look very pumpkin like. Some sort of melon perhaps? It tasted nondescript enough to be a melon, though not very sweet, and are melons supposed to be that crunchy? Perhaps just a very unripe one? No, maybe it was a squash after all. I curried a bit of it anyway, just as an experiment, and it seemed to taste ok. But doubts assailed me. What sort of culinary faux pas was I committing? 'You curried a melon?!' I put the rest aside; one day I will come home to find it ripe or rotten.

One of the nice things about attempting to run a business with a sustainable ethos is that you end up rubbing shoulders with like-minded people. Like Outspoken Delivery, the cycle couriers I share an office with. Like - because the lads at Outspoken have an organic veg box delivered to our office every week - like COFCo, the Cambridge Organic Food Company , whose driver turns up every Wednesday, stops for a chat, and nips out the back for a tinkle. (I wonder - does he have regular customers on the other days of the week that he knows will be in for a loo stop, or does he just have to keep it in?).

With a box turning up every week anyway, it seemed daft to continue propping up Tesco's profit margins, so I signed up to get one too, which I share with a neighbour on the river. So now I prop up the profit margins of COFCo instead. They are such a terribly nice bunch of people I'm more than happy to do that, and as most of the food is sourced locally I'm saving an awful lot of food miles, and hence CO2, compared to my old food habits. It's good on so many levels - so much easier not having to choose between a dozen types of potatoes at the supermarket; so much better not having to strip clingfilm and polystyrene from my tomatoes and stuff it in a bin; good for the planet and good for the soul.

And it's so much more exciting not knowing half the time what you are eating. Hey, I don't care, I'm going to curry that melon anyway - fancy coming round for dinner?

"Beep beep beep beep beep BEEEEEEEEP.... the Government has increased its target for a reduction in carbon emissions from 60% to 80% by 2050. The environment minister, Ed Miliband, said the move was in response to increasing evidence that climate change was happening more quickly than was thought a few years ago. In other news, two supermarkets have dropped their petrol prices below 1 pound per litre. Gordon Brown said that he hoped other outlets would follow suit in passing on the reduction in wholesale oil prices."

I don't know how the BBC announcer managed to keep a level voice in reading the nine o clock new tonight. Or is it only me that thinks its bleeding obvious that reducing oil prices is hardly a good way to encourage people to burn 80% less of the stuff?

A few months ago the government was even calling on OPEC countries to increase oil production in order to keep rising oil costs down. It's mind-boggling. Can they really not see that there is a 1 to 1 relationship? Every single atom of carbon that gets pumped out the ground as oil or gas becomes a molecule of CO₂ that is released to the atmosphere from our engines and power stations. A 10% increase in oil production equals a 10% increase in CO₂ emissions. That's it: end of story. Well, at least until carbon capture comes along, but that could be a long time yet.

So what an 80% reduction in CO₂ emissions really needs is an 80% reduction in oil production. And an 80% reduction in petrol being pumped into petrol tanks. Yet people aren't going to use use less of the stuff if you make it cheaper. It's obvious, isn't it? Surely? Or have the government realised something that I haven't?

My friend Zoe used to be the chief executive of an oil company.

Honestly. You didn't realise I had such high-powered friends, did you? It's entirely true though. Not that her little company was one of the big players in the oil market, I have to admit. The little secondhand fuel pump in a small industrial unit on the outskirts of Brighton was never a rival to Esso, Shell, or BP - but there was a steady bunch of loyal customers who preferred to fill the tanks of their colourfully painted old transit campers with Zoe's refined chip fat biodiesel, rather than the crude stuff the garages sell us.

Sadly, Brighton Biodiesel is no more. I forget the details of exactly why it closed down - there was some exciting tale of Zoe's partner in the business buying a Russian wife on the internet and leaving the country suddenly if I recall correctly. Close down it did though - which is a crying shame. Turning a waste product into something you can power your car with is a very sensible thing to do. I'm all in favour of chip fat biodiesel.

So why don't I like the EU's policy of obliging the oil companies to ensure that road fuel includes a certain proportion of biofuel? Surely that's a good thing isn't it?

The trouble is that recycled chip fat - even in a society wedded to the deep fat fryer - can only ever account for a tiny fraction of the fuel needed to power our transport system. Most biodiesel comes from other sources. Specifically, it comes from palm oil plantations, and palm oil plantations are nasty. The land where palm oil grows well - and a lot of it is needed - is mostly at the moment covered with tropical forest. Forest is a good thing, as far as the earth's carbon budget goes, and chopping it down is not a good thing. Once it's chopped down, the palm oil is rarely organically farmed in harmony with nature either. These plantations are big agribusiness, with heavy machinery and pesticides used intensively. Even if we were just to consider the carbon implications of using palm oil for biodiesel, the worth would be questionable due to the land use change needed. When we consider the other environmental costs, it's clear that it's a daft policy.

The trouble with the EU and American quotas for biodiesel is that they are indiscriminate, and oil companies left to their own devices will simply choose the cheapest option to fulfill their quotas, without taking a blind bit of notice of the environmental cost. Something a bit more sophisticated is needed. Just what, I'm not quite sure at the moment, and frankly I'm hungry and I think I've written enough for now. I'm heading off to the chippy.

There was an article in the paper the other day reporting that some erstwhile professional institution - the architects I think it was - are claiming that residential solar panel installations take 100 years to pay back their installation costs. To provide a bit of balance, the article gave Jeremy Leggett (the CEO of SolarCentury, the biggest solar installer in the land) a prod in the ribs to come up with his own figure. He obligingly opined that that was nonsense: the payback time was closer to 13 years.

Neither number was justified in any way in the article, which makes it rather hard to come to one's own conclusions. Who is right? In the absence of any decent evidence, one's judgement ends up being based simply on who one trusts most. Should it be the architects, who after all are well-educated men who shouldn't really have an agenda one way or the other in the renewable energy debate? Should it be Jeremy, who clearly does have an agenda as his salary depends on flogging lots of solar panels? I have heard Jeremy speak, and although he's obviously very intelligent, I wasn't entirely convinced of his number-crunching abilities in his assessment of the fossil fuel reserves of the world. On balance, I might be tempted to err towards the architects assessment, little though I like the implications.

Better, though, to do a few sums and actually work out a figure for myself. The numbers shouldn't be terribly hard.

Let's start with the wholesale price of solar panels, which I can currently get in for £2.58 per watt. VAT is 5% on residential renewable energy installations, and installers are going to stick on a decent chunk as a profit margin - but still, if you end up paying more than £4 per watt in total, you are getting ripped off badly.

So that's, let's see, £4K for a 1kW solar array, which is likely to produce around 900kWh per year in typical UK conditions. Electricity prices are, what, 11 or 12p per kWh at present? So the array produces around £100 of electricity per year - meaning a 40 year payback time. 5 points for Jeremy, 5 for the architects.

Really, of course, I've badly underestimated the true payback time, for the panels themselves are only part of the cost of installation. A suitable grid-tie inverter can set you back the best part of a grand or more; solar mounting systems are generally hideously overpriced; and installers charge though the nose for their work. I can see that in a bad case, your £4K of soar panels might need another £2K of ancillary equipment, and the installers might wander off with a £4K wad in their back packets. £10K divided by £100 per year: bingo for the architects, and boo-boo for Jeremy.

That is, though, definitely towards the expensive end of the market. And we've forgotten several financial benefits of bunging solar panels on your home. For example, renewable obligations certificates can generate as much - or more - cash per kWh than the electricity itself. If your 1kW array can pay you back £100 in ROCs each year, the equation looks a lot more rosy. Plus - and this is very important - solar panels are not consumables, but assets, so the money you spend on them hasn't just disappeared. 10 years on, it's still there, bound up in the panels, while the money you would have spent on fossil fueled electricity has literally gone up in smoke.

Add in a projected well-above inflation increase in wholesale electricity price and suddenly solar panels become a lot more rosy. How rosy? It's hard to say, isn't it. I think we've now got way too many variables in the equation to come to anything but a very hand-wavy conclusion that the true payback time is probably somewhere halfway between Mr Leggett's guess and that of the architects. Perhaps our simplistic 40 years wasn't too bad after all - if you want my personal stab, that's what I'm going for.

Can we take a 40 year view? Well we could. A few people are prepared to do so. But I'm pragmatic enough to realise that the hordes won't. A five year return on their money is what the masses want.

Governments, on the other hand, can take a 40-year view. Germany is subsiding PV panels to a large extent, which is hurting the taxpayers pockets at the moment no doubt, but is building an enormous base of power generation which will give free power almost indefinately for the future. In 30, 40 years time, they will be laughing and we will be crying. Lets hope our own government wakes up and begins to see solar panels for what they are - an investment for the future. A long term investment, yes, but a worthwhile one. It's the government that needs to take the initiative.

I could say I cycle to work to save the planet. The truth is of course that it's far faster for me to grab my bike straight off the roof of the boat and scoot along the riverbank to Stourbridge Common, up the little alleyway behind the industrial estate, and pull up outside the door of our unit; than it would be to sit in a traffic jam for half an hour in the smog of Newmarket Road.

At least, that's what I used to think.

I was swinging my bike off the roof this morning, when Guiness pounded past with a tennis ball in his mouth. My next door neighbour, Robin, was giving him his morning excerise, and I stopped to pass the time of day. Robin has even more solar panels than I do on the roof of his boat - which is saying something - and a montstrous wind turbine to boot. His boat - like mine - is a perpetual building site, and one or other of us always has a project to sound ideas about. It takes me ten minutes or so to get my head round his latest idea - phase-change materials in an underfloor heating system. Hmmm, intruiging... Finally, I pedal off.

Rhian, on the other side, isn't awake yet, but I stop further down the Common to say hello to Mark and Toni (and new baby) and to admire again the solar panels on the roof of their boat gleaming in the low sun. They were one of my first customers.

Onto the road along riverside, and one of the cycle couriers I share my offices with zooms past with a cheery smile. I wave to a sculler on the river who I used to row with, who nods back - he can't let go to wave or he'd fall in. Further up, the river is clogged with novice college eights. I stop to give some friendly abuse to a crew from my old college, and spend a few minutes chatting to the coach - another old crewmate.

On Stourbridge Common I meet Liz cycling over the Green Dragon footbridge, on her way into my old workplace, BAS. I stop again. 'Coming to the pub tomorrow?"

Steathily, I make it past most of the remaining boats on Stourbridge. But not quite all. Luther is just taking his own bike from his big old Dutch barge. We're both on the Camboaters committee - the association for residential boaters in Cambridge - and we're having yet another skirmish with the Council, who wish to charge us even more for incompetently running the moorings than they do already. There's always plenty to discuss with Luther.

By the time I finally wheel my bike into the industrial unit, the sun is significantly higher in the sky. I could have done it in half the time by car.