Water, Water Everywhere.
Southeast England finds itself facing a Drought Order again. It is unfortunate that the water companies don't put as much effort into doing their jobs as into finding excuses not to- enough rain falls over England in the course of a year to meet all the country's needs, as any cricket or tennis fan will know. The obvious solution is simply to arrange a plumbing equivalent of the National Electricity Grid, but alas, common sense is unlikely to prevail in this case.
There are various things that could be done to increase the efficiency with which households use water, without inconveniencing the owners. The single largest use in an average household is probably in flushing the lavatory- a tremendous waste of painstakingly purified water. My proposal is to install a second tank in the attic space of every new home, to which rainwater running off the roof, and waste water draining from the bath and sinks would be pumped. This would be used solely for flushing the toilet. Of course the action of pumping the water in the first place would require electrical power, which may distress the increasingly energy conscious elements of society, but a small turbine, powered by water falling from the tank to refill the cistern after every flush, would serve to recover much of the energy thus expended.
On the subject of energy, electrical power stations invariably function by using the pressure of super-heated steam to power a turbine. The steam is evaporated, put to work on the turbine, and recondensed. The cycle of evaporation and recondensation of course is exactly what a desalination plant does; the only difference is that in a power station the water/steam is recirculated. (None too efficiently in fact, as anyone who has ever passed a cooling tower on a cold day will attest). With some minor modification, the facilities could just as easily take in sea-water, run their generators and pump out fresh, distilled water to augment supplies.

Dandelion Taming.

Laying a lawn has always been a matter of either buying turf and rolling it directly onto the soil, or raking over the ground before sowing it with seeds and waiting. The latter option is cheaper, but it takes time for the lawn to properly establish itself, during which it must compete with weeds and the perils of hungry starlings, who immediately after seeding will come to regard the whole area as one gigantic bird table. Even in an established lawn, dandelions and other broad-leafed intruders remain a problem.
Weed control fabrics are a cunning innovation- they typically comprise either a tightly woven fibre material, or a polymer membrane full of tiny pores to allow drainage, while trapping the weeds below ground. Following one of my more recent landscaping efforts I was surprised to see blades of grass actually forcing their way up through the pores in one such membrane, which leads me to propose a more loosely woven version of the material, possessed of pores through which blades of grass may pass comfortably, while the larger leaves and shoots of unwanted plants cannot. The placing of such a membrane over a newly seeded lawn would have the advantage of frustrating the efforts of the local fauna to make a meal of it, and the eventual result would be a lawn permanently free of weeds. The membrane would remain flush with the ground, so would not be damaged by the necessities of mowing, and the consequent soil retention means that children could play without fear of trailing mud into their houses and angering their mothers. A logical development is the 'turf quilt', where soil and seeds are laminated between a lower layer of weed-control membrane, and an upper layer of this new material. The quilt could be purchased in sections, either seeded or ready grown, and laid straight onto the most unruly briar patch, creating an instant and resilient lawn.

The Hanging Gardens of Croydon.

The demand for housing in South-East England now far outstrips supply. This is why, before being caught up in one of the now seemingly obligatory sex scandals, John Prescott organised a challenge to developers to design houses that could be constructed for less than £60,000. This was in an effort to increase the availability of affordable houses for first-time buyers. (http://news.bbc.co.uk/2/hi/uk_news/magazine/4749631.stm)
While it is always heartening to see a politician actually trying to solve a problem, rather than merely hoping it will go away, I fear that this scheme ultimately misses the point; it is the shortage of available land which pushes costs up, more than the actual cost of construction.
Logically, the only solution that makes additional living space available without requiring that the surrounding countryside be concreted over, is to build down, into the ground, or up into the sky. Over-reliance on artificial light and the sheer effort of digging rather precludes the first option, which leads me to revisit the 'towerblock' concept. Bad experiences of high-rise living in the 1960s and '70s tend to put people off this concept, as the concrete monstrosities erected at the time created about the least hospitable environment in western civilisation, but there is no inherent correlation between tall buildings and misery- it's all in the design.
A modern tower-block must, in addition to making due allowance for parking, have communal spaces which are light, pleasant and of course easy to police. When it comes to making a pleasant environment, one thing strikes me above all.
Many an inner city resident yearns for the suburbs, and I suspect that, consciously or not, it is 'green space' that they seek. Various studies suggest a link between stress levels and the absence of adequate flora. (http://www.wsu.edu/~lohr/hih/productivity/)

(http://www.plants-in-buildings.com/whyplantsstressreduction.php?PHPSESSID=3acfc0580ee03837fd7a447113b34463) Many people would like their own gardens, but find that this is not practical in the cities. There is in reality no reason why a flat cannot have a garden, other than the additional structural reinforcement needed to support the weight, and the fact that all except the top storey will inevitably have a roof. Of course, suitably imaginative use of mirrors and light-pipes can bring in much of the absent sunlight even with a covered garden, and the difference can be made up with artificial lighting. The lack of rainfall is readily compensated by use of artificial irrigation.

The tops of such buildings could also become communal parkland. With enough such buildings the distinction between town and suburb will begin to blur, and the image of the menacing, inner-city estate can finally be consigned to history.

The 'Hydrogen Economy' has been attracting much interest in recent times, as the price of oil continues to rise and concerns about CO2 emissions reach near hysterical levels. The major drawback of hydrogen as a fuel is one of energy density- the sheer quantity of hydrogen required to supply enough power to run, say, a car. This coupled with the inherent difficulties in storing free H2 (Being such a small molecule it is not readily constrained by the walls of a gas canister, nor is it practical to compress to a liquid except by cryogenic cooling), has led to various attempts to develop metal hydrides as storage mediums. In the case of transition metal hydrides, I rather doubt that they can ever hope to attain the 6 wt% target deemed necessary for commercial viability.(http://www.eere.energy.gov/hydrogenandfuelcells/storage/metal_hydrides.html) Lighter metals may be more promising, but in all cases the storage medium tends to be a solid.
I have amusing visions of people shovelling wheelbarrows full of this new wonder-fuel into their cars, like coal-stokers in the age of steam, but do not consider this an ideal solution.
The simplest system for hydrogen production is necessarily the one I find most appealing- I have a simple mind- and is of course the reaction of water with group I metals, the cheapest being sodium.
(This produces sodium hydroxide, converting which back into usable fuel again is a rather energy intensive process, but this particular tirade is about energy storage, not energy production).
Ideally, the fuel of choice should be a liquid, allowing it to be pumped into the car at the petrol station, and out again for reprocessing, once expended. While pumping molten sodium into one's car at 98 degrees celcius is possible, I fear the HSE would raise some objections, so the only hope is a colloidal dispersion.
Consider a fine suspension of sodium (or sodium hydride) in an inert liquid- I would suggest silicone oil, which springs to mind because it's notoriously unreactive, and I've just been having a discussion about breast implants for some reason. A surfactant would probably be needed to render the colloid stable, but something could no doubt be devised, possibly an ether of some kind.
Water would not be miscible with the resultant suspension, so hydrogen would be produced instead by mixing it with a linear alcohol, producing in the process a sodium alkoxide. I hope, for the sake of elegance, that this alkoxide would either remain dissolved in the silicone oil, or form a colloid of its own. If necessary a second surfactant could be added to the mix to facilitate this.
The sodium dispersion would be reasonably stable in air, as the individual colloid particles would be coated in a protective layer of oil, so I am now able to envisage people pulling up to the 'colloid station', having their used fuel pumped out as fresh fuel is pumped in, leaving behind a slurry of silicone and sodium alkoxides to be recycled.