Marc Gawley

When the wind blows

June 9, 2014 1 Comment

I looked today at investing into a company setting up a small wind turbine. I’ll keep the numbers round for confidentiality reasons.

£700k start-up costs, with a 75% chance in any year of generating enough energy to sell at 5p / kwhr to the grid for £30k.

10% of revenues go to the site’s landlord, and a flat £15k per year to the manufacturer for a full maintenance contract.

This is clearly not viable. Fortunately there is an additional subsidy of 18p / kwhr (rising annually) due to the Government’s Feed-in-Tariff.

Nothing about this site will get cheaper over time. Assuming a life span of 25 yrs and a 10% discount rate, the turbine and other start-up costs would have to drop from £700k to £100k for future such ventures to start to look interesting sans subsidy.

In the UK the total subsidies needed for all such schemes are added up, and then divided out amongst all consumers’ bills, so it’s not clear to the general public just how much more expensive (it appears 4x as much) some alternative energy sources are costing.

Future Governments change their minds about policies. And for that reason, I’m out.

Filed under economics, science Tagged with energy, FIT, subsidy, uk, wind

London’s protected views

March 2, 2014 2 Comments

This diagram in the Economist captures 10 of the 13 protected views in London:

The London Plan protects views of St Paul’s Cathedral and the Palace of Westminster, as seen from London’s larger parks. You must, for example, be able to see both buildings from a specific oak tree on Hampstead Heath. Erecting tall buildings behind them is discouraged, too. These protected views help to explain why tall buildings are rising in such a dispersed pattern. The Shard will not get neighbours anytime soon, as it is wedged between two viewing corridors. In the City, towers are scattered instead of crowding around transport hubs, as economic theory might predict. Their odd designs—described by nicknames such as the Gherkin, the Walkie Talkie and the Cheesegrater—are in some cases a means of avoiding imposing on St Paul’s. Only at Canary Wharf, which is too far east to spoil many views, do cuboid skyscrapers rub together in the way they do in other big cities.

Filed under Uncategorized Tagged with London Plan, Protected Views

How big a problem is HIV

January 26, 2014 1 Comment

If you collected all of the HIV from the world’s 30 million sufferers, it would fit onto a spoon. [source]

Filed under Uncategorized

Being poor in a rich country

October 26, 2013 4 Comments

The FT has an article today with ‘the one chart that explains the world’.

The vertical axis refers to the distribution of global incomes. The horizontal axis segments citizens of different countries by 20 income groups. As you can see, even the poorest people in Germany are very much richer than those in the Ivory Coast, for example. The person compiling the data, Prof Milanovic, finds that about half of one’s income depends on the average income of the country in which that person was born.

It reminds me of a post on global income distribution I made previously, basically that the poorest 5% of Americans earn more than the richest 5% of Indians. Source .

India led the world in GDP before the industrial revolution, when population meant productivity, and India had the largest population. Following the industrial revolution, India entered a long period of economic stagnation. India used to account for 33% of the world’s GDP, then fell to 3%. Source.

Filed under economics

Don’t mention the solar panels

September 28, 2013 Leave a comment

On a flight this morning I began to think that the Bjorn Lomborg quote I heard yesterday couldn’t be plausible:

Germany once prided itself on being the “photovoltaic world champion”, doling out generous subsidies – totaling more than $130 billion to citizens to invest in solar energy…by the end of the century, this will have postponed climate change temperature increases by 23 hours.

So I tried a quick back of the envelope calculation:

German population = 70m

Global population = 7bn

Ratio = 1/100

—

Number of years solar panels last for = 20

Years over which CO2 emissions have and will accumulate before the bad temperature rise (say 2100 – 1900) = 200

Ratio = 1/10

—

Reduction in CO2 emissions of Germany = 1/100 (the article gives a less than 1% current total supply by solar)

—

Germany’s level of emissions during these 20 periods relative to global average over 200 years = x2

—

Total portion of CO2 from global total that will be avoided =(1/100) x (1/10) x (1/100) x 2 = 2/100,000

—

Number of days over which CO2 emissions occur = 365 * 200 = 70,000ish

Over 1m Germans have solar panels installed. Number of days of CO2 emissions avoided from these, i.e., how much extra time is bought before a catastrophic temperature increase = 70,000 x 2 / 100,000 = 1.4 days

Wow. Well done. I definitely feel less bad about my flight now. Not that I was.

I came across Without Hot Air several years ago and found it to be very credible – same approach, back of the envelope physics…I seem to have just complimented myself on being very credible. I’d best stop myself here. It’s not impossible I’ve missed something obvious out of the above…

Filed under science, surprising numbers Tagged with benefit, climate change, CO2, cost, germany, solar panels

Sentences of note

September 27, 2013 1 Comment

Things I read / heard this week:

Germany once prided itself on being the “photovoltaic world champion”, doling out generous subsidies – totaling more than $130 billion to citizens to invest in solar energy…by the end of the century, this will have postponed climate change temperature increases by 23 hours.

Source: Bjorn Lomborg

“If I was Saddam Hussein and I really wanted to make a virulent flu virus, I would take a recently drawn flu virus, I would passage it through groups of 20 prisoners, I’d take the virus from the ones who were dying, and I would passage it through more. Anyone could do this. You just have to be unscrupulous enough.”

Source: Peter Doherty

People pay more attention to the number killed in a natural disaster than to the number of survivors when deciding how much money to donate (estimated at $9,300 per person killed). The number of people affected in the disasters, on the other hand, appeared to have no influence on the amount donated to relief effort

Source: Journal of the Association for Psychological Sciences

Filed under surprising numbers Tagged with charity donations, climate change, german, solar panels

Bronze [at my] age

September 22, 2013 Leave a comment

I’ve started running again and discovered the weekly 5km park runs organised across the UK.

Yesterday’s 5km run at hilly Hampstead Heath was better than expected:

My first thought was, “wow, 3rd, and at my age!.” But inspecting the table it’s quickly clear that I’m not relatively old compared to the other top finishers.

It was the second highest attended race in this location’s 3-yr history (183 finishers) so plenty of data to play with which I put into Excel…

In terms of straightforward averages by ages, or median times, I could see no patterns.

Focusing instead on we ‘elite’ runners, ahem:

Considering the top 3 runners in each age group, it does seem that mid 30s is the sweet spot for this kind of distance (for fit non-professionals, at least). The effect is even more pronounced upon removing potential outliers and considering the times for the 3 runners finishing in 4th to 6th place.

Investigating a little on the interwebs, this seems to be a real relationship. For example, data regarding aging and endurance performance for 10ks shows this:

Anyway, hats off to Jason Merron who was running around with a baby-filled buggy and still finished in the top half. I don’t know what the adjustment factor is for that…

Filed under Uncategorized Tagged with 5km, age adjustment, hampstead heath

No claims bonus

September 10, 2013 2 Comments

I saw this ad on the tube:

And was struck by the types of claims made:

Most trusted by mums
Brand midwives recommend most
No 1 pregnancy supplement brand
Award for innovation in vitamins research

None of these is a scientific claim relating to an actual improved pregnancy/birth outcome. Indeed, Vitabiotics have had several of their adverts banned by the ASA for making unsubstantiated medical claims. See here, here, and here.

This page on their website has graphics corresponding to these claims, with links to the sources, as well as to the British Journal of Nutrition which published a paper that is the source of Pregnacare’s most scientific-sounding claim that:

…landmark in research was achieved … showing that Pregnacare tablets reduced the number of small-for-gestational-age (SGA) infants (low birth weight for time of birth) relative to the placebo.

The study of over 400 newly pregnant women … was the first ever reporting of clinical findings … showing that supplementing with a specific multivitamin supplement helps reduce the number of SGA infants born.

Except it’s not an actual working link, just a graphic which has the same visual appearance of the real links during a mouseover. I tracked down the paper because I had nothing better to do on a Monday night.

The researchers tried to recruit 2,385 socially and economically deprived mostly immigrant pregnant women in Hackney, East London. Only 402 subsequently participated (for example >10% of the sample were unable to speak English and therefore could not give consent). The 402 were given Pregnacare or a placebo tablet, but most dropped out leaving only 150 mothers who took the tablets regularly. This is the outcome:

The intention-to-treat analysis shows no difference in SGA numbers. There is in those fully compliant, and although that is in favour of Pregnacare, those receiving treatment were more likely to have a low birth weight child (even after a longer gestation period) – which is a more serious issue. (See this v this).

As far as I can see, after 1 hour of my life that I’m not getting back, giving vitamins to a multi-ethnic group of low-income pregnant women, of which 72% had a vitamin D deficiency to begin with, “may,” in the smallest print showing on the advert, “benefit those with nutritionally inadequate diets”. No shit. But if you’re short of time, pregnant, and read “Pregnacare” you may well take the cognitive shortcut that these tablets will help you take good care during your pregnancy.

Filed under science Tagged with clinical study, health benefit, pregnacare, scientific claim

Taking money from mathematically challenged customers

August 25, 2013 Leave a comment

A couple of pricing tricks I’ve come across in the last week to take money from non-thinking customers.

Calling £9 equal to €10, then you need to know that the probability of Wizz Air being over an hour late (probably plus another 15 minutes padding in the flight duration in the first place) is somewhat in excess of 10% for this to make sense. I checked flight stats here and of course no airline has been an hour late that frequently this year. Tim Harford covers why you should not normally take out insurance anyway for things that won’t wipe you out.

I won’t comment on the send me an sms for a pound.

—

I was in the market for a new phone, and found this pricing on O2 for an HTC One. Which option would you go for (this is just for the handset, the Airtime plan is separate and not dependent on the option picked below)?

The more you pay today, the less you will pay each month, indeed. Come to daddy. And surely the last option is only there as an anchor so that people believe they are getting a £600 phone. No-one’s that stupid?

Anyway, whichever option you went for, you’re [possibly] wrong: it’s £422 unlocked on Amazon.

Filed under Uncategorized Tagged with O2, on time arrival guarantee, Refresh, Wizz Air

Zero waste, zero point

July 3, 2013 3 Comments

I attended a talk by Bea Johnson on ‘Simplifying Your Life’ this week. Her family has completely changed their lifestyle, e.g.,

…if your hair is short, you also have the “no-poo” option: rinse your hair, massage baking soda in, then rinse, with vinegar for shine

to reduce to virtually nothing the amount of household waste they generate that ends up in landfill.

This got me thinking…

It seems that the UK produces roughly 250 kg of landfill waste per person per year. Corroborated here.

Assume this is compacted to a volume with a density half that of water.

There are 25m households in the UK, with an average of 2.4 persons each.

This source says 33 sq m per person (which sounds about right given the above):

With a ceiling height of 3.3m, this is 100 cubic metres of space per person.Which,

allowing for lifetimes of 100 years, the entire landfill waste generated by a household would occupy around half of the volume of the house.

OK, I’m probably off by a factor of 2 here and there, but this doesn’t seem to me to be so big an issue to need to solve so drastically, especially given that the amount of surface area covered by housing in the UK is quite small anyway.

Filed under surprising numbers Tagged with landfill waste, per household

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