Our solar and wind power systems

Over the last few months I've been asked by a few people about what we've done in terms of PV and wind turbine electricity generation, so I thought I'd lay out the basics of our systems here. I am not a qualified electrician, but I do understand electricity and the dangers associated with it, and I spend a lot of time reading datasheets and learning about how to do this stuff before starting. If you do go down this path then make sure you have a clear understanding and be careful. Having said that, in my opinion, there is nothing stopping any competent DIYer from building an effective and useful off-grid system safely and at relatively low-cost. There is lots of information out there from manufacturers of bits of kit and from enthusiasts and YouTubers.

So, what do we have?

Two systems:

1) A standalone system that we use almost exclusively for charging our cars. This system can supply 4kW max to the car charger, and can also store energy in a 24kWh (nominal) 48V lead-acid battery bank. This system is housed entirely in the shed and was the first one that I put together. It has been in use for 5 years now, and seems to be working as well as it did when first installed. We have had one failure very early on (the inverter), but the manufacturer sent new parts and it has been working without any faults ever since. The battery bank was expensive (~£2000) and being lead-acid needs regular water top-ups, especially in the summer, so is a bit of faff but seems to be holding up ok. When I installed it I estimated that it would have about 5/6 years lifespan, but it still seems to have reasonably good capacity, so I'm not thinking about changing it yet. Last year I added a manual changeover switch so that we could run the house from this setup when the cars were fully charged, but the 4kW limit was a bit irritating as we'd often forget and switch on the kettle at the same time as the washing machine and the inverter would cut out (not popular with the gamer in the household). The more normal mode of use (pre-COVID) was that the battery bank in the shed would charge up during the day and then be transferred to one of the cars in the evening. This is not a nice mode of use for lead-acids (being fully discharged daily), so I set the voltage limit very conservatively which means that we only actually use about 10kWh of the 24 available in order to improve the battery lifespan. This system has a total of 6kW of PV panels (second-hand 5 years ago) and a (fairly poorly sited) 500W wind turbine, and provides about 70% of our car charging needs throughout the year. For about 7 or 8 months of the year we use this almost exclusively, with the exceptions being when we have multiple long trips on consecutive days. We usually do one or two round-trips to town per day. A round-trip is about 25 miles and has ~1,300ft of climb. I spent a bit less than £5,000 on this when I installed it and suspect that it has paid for itself around twice over by providing electricity for about 50,000 miles of driving (probably actually a bit more than this).

About once a month in summer and a couple of times through the winter I spend a happy 20 minutes topping up the battery electrolyte (that squeezy bottle is perfect for the job).

Rather dusty bank of 16 Trojan T105s. Still going strong after a bit more than 5 years.

Very impressed with this 4kW Voltacon inverter/charger. Not very proud of the wiring job mind .

The watering kit for the Trojans is a god-send. Would be a nightmare having to do 48 individual caps by hand each time.

What it's all about.

These QUBEV chargers were very cheap and seem to work pretty well. Box is getting a bit rusty though!

2) A system for the house. This system is relatively new and has a newer model inverter that can supply up to 8kW. We have a 9kWh LiFeP04 battery bank on this which is charged from 3kW of (again second-hand) PV panels (soon to be expanded to 4.5kW). We are also considering another 500W wind turbine, in a better site than the one for the car charging system. The 8kW capacity means that we have not yet hit the limit using our normal domestic load habits, and we can run the washing machine, dishwasher and heat-pump simultaneously although this almost never happens in practice! It is on an auto-changeover switch, so when the battery runs out of juice it switches back to the mains. As this was only recently commissioned (in the middle of summer), I don't really have a feel for how much of our usage this will provide when the PV is less productive. As I type this we have been "off-grid" for about 48 hours, including one rather grey and one fairly sunny day. This includes a couple of loads of washing, a couple of dishwasher runs, the immersion heater and a batch of cupcakes (yum). My rough calculations indicate that to be completely off-grid through the winter, and using the heat-pump for heating, would need about 30kW of PV and about 20kWh of storage: probably not realistic, but we'll keep adding bits and pieces of generation and see where we get to.

Fancy new Pylontech US3000C batteries. Built-in BMS will talk directly to the inverter, so hopefully all properly managed and no more faffing with the squeezy bottle.

Fancy new 8kW inverter connects to WiFi and does all sorts of performance logging etc. Even the app (I'm a bit allergic to apps these days) works pretty well.

 Electric cars: some opinions after a few years

So we own two electric cars, a 24kWh Nissan Leaf that we've had for a bit over 6 years now and a Tesla Model 3 SR that we've had for about 2 and a half. They are both used regularly and we've put about 55,000 miles on the Leaf and 35,000 on the Tesla.

The state of the Leaf:

1) It's lost one "bar" from it's battery state meter (this is a Nissan thing) and seems to have lost between 5% and 10% if its range from when we first got it. Significant, but still fine for a couple of trips to town and back and some running around which is its primary mode of use. Seems to be happening very gradually and at this rate I reckon the battery will still have usable range at at least 150k miles.
2) It doesn't feel noticeably different to drive since we first got it. Maybe the suspension is a bit squishier than it used to be, but that's not really surprising considering the state of the track to our house. Acceleration and steering feel the same as the day we bought it.
3) I still really like driving it as it just feels like a normal car and is comfortable and easy-going.
4) Until this year when we paid ~£500 for new rear brakes and handbrake cable to be fitted (I was too lazy) we'd spent about £100 per year on maintenance. Apart from stuff like windscreen wipers and tyres the only repairs were a new rear fog-light (got shunted by a van that broke it), and the windscreen washer motor that got broken when it got crunched by a bit of less than careful parking: the child in question will remain nameless :-)
5) It's now getting pretty scruffy inside as I'm a terrible slob. Maybe I'll have a proper go at cleaning it one day.

Executive summary: still a decent "normal" car with plenty more miles of use in it.

The state of the Tesla:

1) At ~35,000 miles it's range is as far as I can tell exactly the same as it was when new.
2) It has all sorts of squeaks and clunks. None are functionally problematic, or even easy to identify the source of, but a tad irritating for such a low mileage vehicle.
3) I've been unimpressed by the servicing in Cardiff (one experience). They broke plastic clips, sheared off captive nuts and didn't get rid of the squeaky suspension. 
4) The range, acceleration and handling are all amazing and it's great on long trips. A really useful vehicle.
5) The under-trays fell apart very quickly (again probably to be blamed on our track) and have now been replaced by after-market aluminium ones.

Executive summary: lousy build quality (especially for the price), but really useful for long trips and fun to drive.

I actually prefer driving the Leaf as it has fewer squeaks and clunks and feels more like a normal car, and if it had the same range and charging network as the Tesla I would choose the Leaf every time. I guess that's just the effect of it being built by a long-established car company rather than a relatively recent entrant to the market.

Cost of ownership:

1) Because we've got an off-grid solar PV with storage setup we do more than half of our charging from that for "free" (around 70%). I don't remember the total cost of installation, but it was around £5k. Over the last five years I reckon it's saved us double that in equivalent diesel costs. Proper "Vimes boots" stuff.
2) Maintenance is absurdly cheap compared to the diesels we were running before: probably around 20% I think,
3) The Tesla will eat tyres when driven enthusiastically: I haven't kept track of this, but I suspect that we spend about 50% more on tyres than for previous cars, so it's significant. The Nissan doesn't suffer from this.

My conclusion:

I basically love electric cars. They just work with almost no maintenance in a way that the diesels we owned never did. They are cheap to run, quiet and relaxing. Slightly different from diesels on long runs (but barely in the Tesla). Even with the "standard range" Model 3 I can get from Aberystwyth to Edinburgh in 2 stops, which is what I'd do anyway, and even with charging I get there in about the same time as the Google Maps estimate.

Brexit (arrgggghhh)

I was heartbroken when the brexit referendum result came in and I still think that it is insane to leave the EU, but that is now (apparently) inevitable and we'll just have to put up with it.

There are a couple of things that I think are worth saying about the whole debacle that are not the usual "we're going to be poorer", "we're condoning racism" type of things. In the grand scheme of history I suspect that brexit will be seen as a bizarre sideshow to the slow-motion, multi-vehicle car crash that is currently unfolding in Europe and the wider world.

Climate change is rapidly altering large tracts of farmland in Africa, the middle East and Europe. The effects of this are I suspect going to be very dramatic in the near future, probably including famine and/or crop failures in large areas leading to physical and economic hardship on a relentlessly increasing scale. This is likely to lead to the abandonment of already marginal farmland and migration of large numbers of people. People will move Northward in increasing numbers by crossing the Mediterranean Sea and placing further pressure on Southern European states such as Greece, Italy and Spain which will also be suffering from changes to their climates. I find it difficult to imagine the effect that this will have on the EU, but I suspect that at some point it will result in dilution or abandonment of the free-movement of people and further tightening of borders. There may also come a time when the richer Northern states decide that they are better off without the poorer Southern states. This is likely to prove very difficult for the continued coherence of the EU as it currently stands. I have no idea of what the implications of this will be for the U.K. or Wales.

Populist and increasingly right-wing governments are also popping up in increasing numbers and are unashamed or actively proud of destroying international, collaborative endeavours whether they be arms treaties, emissions targets or trading agreements. This does genuinely seem to be a global phenomenon with multiple European states, the U.K., the U.S., India, Australia, Russia and various other states wandering down this path. Quite where this ends is difficult to imagine, but it is not a large leap of the imagination to see wars and isolationism. Brexit seems to be a symptom of this affliction and also provides fuel to the fires of other similar isolationist projects in Europe and around the world, but is I suspect pretty much irrelevant for the vast majority of people beyond the U.K.'s shores.

Rebellion, extinction, energy and making a difference (or not)

I have a lot of time for the ideas behind the XR movement (I am basically a bit of a lefty, eco-nut), but I also have some significant problems with the organisation and its likely effectiveness. Because I am good at lists:

1. Personally I really struggle with demonstrations as a mode of engagement. I understand that they are very effective at raising awareness of issues and getting media attention, and for that I am very grateful to the people that go out and demonstrate. It's just that personally I don't really feel able to walk around shouting into the void or the face of a policeman.
2. Actions that seriously impact on people's lives can in the short term play an awareness-raising role and garner support from a small segment of the population, but also rapidly attract negative publicity and backlash from the mainstream, yet-to-engage populus.
3. A rebellion that will be effective at rapidly stopping CO2 and methane (CH4) emissions (my current top priorities) will have to be far more dramatic than stopping some traffic in London and holding people's assemblies. I genuinely think that anything short of a full-on coup that removes all politicians and replaces them with a dictatorship of scientists and engineers is not going to make a faster and more effective change than the current rather pathetic progress. I suspect that this is not what most XR foot-soldiers would consider to be a positive outcome either.

Whilst 1) and 2) are arguably minor problems that it might be possible to ignore or get around in one way or another, for me 3) is a showstopper.

We really need to take as much action as possible now, and I suspect that XR is not currently having a practical or significant effect on CO2 or CH4 emissions reduction. I understand that XR sees political reform as fundamental to setting up a cleaner, greener, fairer world, and I agree that this would be a fantastic thing to achieve. I just don't see it happening anywhere near fast enough, and I also don't think it will necessarily immediately lead to reductions in CO2, CH4 and other forms of climate-changing pollution.

It might be worth looking back at what has actually helped to reduce the growth in CO2 emissions in recent years. Anyone that has been watching the changes in the UK electricity grid (see https://gridwatch.co.uk/ for live data) will have noticed that wind power has become a major contributor and to a lesser extent solar PV has also helped to push up the renewable energy share. There is another crucial low carbon contributor to UK electricity generation that provides a consistent and reliable supply: nuclear. In my opinion we at least need to maintain the nuclear generation capacity that we have if we want to keep the lights on whilst switching from fossil-fuels to renewables. Attaining a position where we have a near-zero-carbon grid with some significant "always-available" power sources is orders of magnitude easier than with only intermittent sources such as wind and solar: look up the research papers that have studied this problem, they are really interesting (eg. https://scholar.google.com/scholar?hl=en&as_sdt=0%2C5&q=100%25+renewable+grid&btnG=).

My take on this (with a few rough figures): the contribution of wind power and solar PV is fairly quickly increasing, and will continue to do so for a while as it seems to be a good way for rich people to make more money. Nuclear currently provides around 20% of our power (a bit more if you include the significant amount that we import from France which has mainly nuclear power generation). Once the wind/solar PV component increases by another factor of 2 or so the benefit in reduced CO2 emissions will start to decrease unless we start to install large amounts of energy storage: probably battery storage initially. This is already happening and I expect that it will continue to, although it's not clear to me where this will end up: massive centralised battery/super-capacitor storage, or distributed in-home/factory storage, or liquified air storage, or something I don't know about. I guess some sort of mixture will come about... it's going to be interesting to see.

It's worth remembering that the wind and solar capacity that has thus far been installed has been commissioned and paid for within our current (albeit very broken) political and economic framework, and if we are to limit the looming climate catastrophe then I don't think that we have time to change "the system" before taking action. We need to continue to push the broken, capitalist, plutocratic jalopy along the road towards the recycling centre. All of the really boring, play-along strategies like signing up for so-called green energy suppliers, buying expensive electric vehicles, insulating our houses and installing expensive heat-pump heating systems are the best weapons that those of us that can afford it have available to us. We have no real choices that will make a bigger difference on a reasonable timescale.

Those expensive electric vehicles will form the basis of a secondhand market that will allow less well-off people to move away from petrol/diesel; increasing the volume of heat-pump sales will help to make the industry more competitive and hopefully wake the government up to the potential greenwash that they can garner from backing such technologies. Much as it irks me to say it, it seems to me that offering political and economic capital is the most effective whip that we have for forcing government action on climate change.

My Life as a Serial Quitter

Those of you that know me will be aware that I recently quit my job at Aberystwyth University to go and take up a post on a graduate training placement as a school teacher at Penglais School. You will also probably be aware that I lasted for only 10 days at school. Some of you might be interested to know how/why this came about. If not then stop reading here...

Why did I quit being a lecturer?
It's a long list. The overall reason was my growing dislike for what I was turning into (gradually getting more and more grumpy and less and less enthused). Underlying this was the way that the job was changing and the overall feel of the university. I would like to stress that I still think that the Computer Science department at Aberystwyth is full of great people who are trying really hard to do as good a job as possible. It's just that there are lots of weird and wonderful obstacles being put in their way. A few specifics:

1. Mauritius. The Mauritius adventure that Aberystwyth University has embarked upon is so ridiculously ill-thought-through that it makes me want to cry. For many years we taught (successfully) an MSc program in Singapore. I never liked it much for reasons that are not relevant here, but at least it was properly managed, had significant numbers of students and paid for itself. No-one seems to have taken this experience into account when setting up Mauritius which has resulted in, what is in my opinion a disastrous commitment. The impact on workload and staff morale (at least in Computer Science where there are a only small handful of students enrolled in Mauritius) is enormous. I have never seen a definitive count of the number of students in each cohort, but I'm almost certain it is in single figures for every year of recruitment (onto Computer Science). Flying people back and forth to teach a tiny number of students has significant impacts on teaching quality and workloads in Aberystwyth too.
2. Tell Us Now. Tell Us Now was conceived as a way for students to give immediate feedback on how their education was progressing and on any issues that they felt needed addressing. The idea is simple and reasonable, but the implementation was awful. In the early stages anonymous comments were being passed on directly to staff members, even when they were outrageous and verging on libel and racism. The fervour for the project and the way that it was implemented left many staff  feeling discouraged and defensive about their teaching. This included people who had received awards for their teaching from the students in the same (or previous?) year. The "traffic-light" system for the (conflated in my mind) MEQs meant that almost everyone got amber or red and was made to feel inadequate.
3. Research. I realized after a long time that more and more of the research that I was doing was not really because I thought it was of fundamental value or importance, but because I knew that I could get the funding to do it. It's always been a bit like this: you chase those ideas that look "fundable", but when you get them you try to squeeze in bits of work that are more exciting
   and interesting. I just ran out of energy for trying to do this any more.
4. Time Pressure. Pressure on time has always been there, and a few years ago I went down to 4 days per week to try to maintain my sanity. Unfortunately it became increasingly difficult to stop work commitments from devouring the one day per week that this was supposed to preserve for other things. After an unsuccessful attempt to get put back on to full pay (5 days per week) I finally admitted to myself that I wanted to get out before I hit the mental buffers again.

There are many other lesser things, like being expected to take on significant responsibilities (such as health and safety) that I did not have the training or time to address properly, but I think that those are present in so many jobs that they are perhaps less significant.

Why school and why did I quit?
My kids are currently going through school, and whilst many of the teachers seem to be committed and keen to do the best that they can, some of what happens to them seems very odd. I was keen to see how and why these things were happening and to try to do my little bit to make things a little bit better. Naive? Me? Yes. The example of something that I didn't understand (and still don't) that I often recount is the occasion when my daughter was given a past GCSE paper to try after only 3 weeks of studying the GCSE course for the subject. Why? I still don't really have an answer, because I only lasted 10 days. But I suppose it's to do with training them to answer exam questions, sometimes at the expense of really getting to enjoy and understand a subject.

Why did I quit? Mainly because I lacked the energy to extract what I needed and wanted from the school. I was signed up for a GTP (graduate training placement). I was told from the outset that it would be hard work and I was prepared for that. As it turned out, the amount of work that I was expected to do was not too bad at all. Preparing for and delivering lessons was perfectly manageable, although I suspect that once homework and marking had properly kicked in it would have been a bit harder to keep up. And when I had moved up from 60% to 100% teaching load harder still, although hopefully I would have been a bit more efficient by then. Still, I don't think that the workload was close to what was expected at the university. This was a (nice) surprise to me. So why? Once again, there were a range of reasons, and I'm not going to detail them in depth here, because I don't want to accidentally release any potentially confidential information. But here are the basics:

1. There was (almost) no training. I had expected to be given some training in the school. I was given no significant guidance about the day-to-day processes in the school. This included how to use the systems that were in place for dealing with poor behaviour. It was (a very significant) issue related to behaviour management processes that made me decide to walk away. On the whole the children were great and I managed to keep the lid on the classes that I had. There were some people that required more effort than others, but on the whole I felt that it worked ok. I do not however have any external reference for this because nobody observed any of my lessons or gave me any feedback on how I was doing (I taught a total of 19 lessons).
2. It was not clear what I should teach. I was given a scheme of work spreadsheet which consisted of (mainly) single word topics that should be covered with each group. These were at the level of things like "sequences" or "fractions", so I went off and planned a few lessons in advance on these topics. After giving my first lesson to one class which I shared with another teacher I discovered that the scheme of work had been changed by him so that the topic that I taught was no longer supposed to included. No guidance was given on how long each topic might be expected to take or what aspects of it might be appropriate for each year group or set.
3. Important information was (very) difficult to get. I tried to get hold of information about various things including the school's child protection policy and the literacy and numeracy framework strategy. I asked a few people and I was given a one pager on the CPP, but it all seemed to be very difficult to get hold of.

There were other issues, such as piles of recycling, old toner cartridges, disused computers etc. lying around in the office, corridors and classrooms, a leaky roof etc. which just smacked of neglect, but I suppose these are just symptomatic of the lack of resources available to the school.

I am not proud of walking away after only 10 days, and I was somewhat unfair on the school in doing so (I didn't give them an opportunity to address the issues), but I just couldn't face having to become the "thorn in the side" that I feel that I have been for so long inside the university. I was hoping to be able to slide unobtrusively into the bottom layer of the school and teach the children without having to stick my head above the parapet too often, but I rapidly came to feel that in order to even meet basic standards (such as adhering to the behaviour policies of the school) I was going to have to start going over people's heads and generally being a nuisance. So I walked away. And conveniently (and true to form for all large organisations) I had not yet been given a contract, so could do so with impunity. I feel guilty for the children that I have left in the lurch and (a little) for the school, but mainly I feel that it was the right decision for me.

Marie has just pointed out that this sounds really miserable. It's not! I am happily tinkering away in my shed (both physical and virtual) to try to get some saleable products together. It's taking some getting used to, but I will de-institutionalize myself and blossom into... something or other!



Postscript: The more astute amongst you will notice that I have not mentioned the school uniform issue. This also irritated me, but was not a significant contributor to my leaving. I continue to believe that it's a red-herring and that it just provides a wonderful focus for lots of time, energy and anger on both sides of the debate. If you are interested in learning more about it then I suggest going to scholar.google.com and searching for something like "school uniform academic achievement".

Our Nissan Leaf: experience so far

It's getting on for a year now since we bought our first electric car, an ex-demo Nissan Leaf. So far it's done exactly what we wanted and expected. First and foremost, "it's just a car". It's not some weird experience to get into and drive, you just get in press the button and drive it like any other automatic car. We have had no technical issues with it yet, and it still seems to behave exactly the same way it did when we bought it. I'm not sure how many miles we've done, but it must be around 8,000 I think.

Pros:

1) It's just a car

2) It gets you to where you want to go

3) It's comfy and quiet

4) It's cheaper to run than our diesel burner (quite a bit cheaper, but sorry no I don't have exact figures)

5) The traction control is pretty good in the snow

6) There is almost nothing to service/worry about servicing

7) It has good ground clearance (which matters where we live)

8) It does 0-60mph in just over 9 seconds (we timed it very precisely using an Android phone stopwatch and the speedometer)

Cons:

1) People assume that you believe that you are saving the world by driving an electric car

2) People feel the need to point out that the electricity that you use generates carbon dioxide

3) People feel the need to point out that electric cars are crap (even though they've never owned one)

4) It is only capable of doing about 95% of the trips that we do (we drive our other car for the longer trips)

5) There are no fast chargers around Aberystwyth

6) I don't get to drive it much (I usually drive the diesel burner)

Conclusions:

I like it. It's cheap to run, and hopefully will be cheap to maintain due to all the complicated bits that are missing (like the engine, clutch and transmission). It's irritating that everyone assumes that you are a naive tree-hugger who doesn't have a clue about anything technical because you own an electric car. It's pretty much the ideal second car as far as I can see: the range limit (about 85 miles if you drive conservatively on hilly Welsh roads) is a bit limiting and precludes it from being our only car, although if there were one or two more public fast chargers around it would be a lot more viable. If it had a range of (say) 200 miles then I think I would be happy to have it as an only car. Nissan say here that this is going to happen soon, but we'll wait for an ex-demo/secondhand one I expect. Please don't bother telling me that I'm an idiot for buying this car, there are many other better reasons for calling me an idiot.

Teaching and learning

I've been doing some mulling and wanted to post something, partly to get ideas straight in my head, and partly to try to let people know how I (and at least some of my colleagues) feel about some of the issues around delivering modules to students in university. So here goes...

Teaching is mainly quite fun and hard work, but is not quite as simple as it may seem. Learning should also be mainly quite fun and hard work, but it is also not quite as simple as it seems. Particularly in a university context. Teaching my kids to ride a bike is an example of a kind of teaching that is very easy for both the teacher and the learner to appreciate: you know when you've got it wrong (it hurts) and you know when you've got it right (because it doesn't hurt). Riding a bike is a difficult to master but simple skill. You will often encounter very similar conditions in which you ride a bike. You may choose to ride your bike around Nant-yr-Arian or up and down steep hills, but you will be deploying the same basic principles many times over. You may need a few new ones to deal with new situations, but you are essentially building on a core principle and honing your abilities.

Unfortunately teaching and learning at university is nothing like that. Writing computer programs to implement software systems uses a set of skills that you could choose to view in this way. You will use variables, parameters, functions, loops, if statements etc... each time you write a program (assuming you're using Java or C or something similar), and you could argue that this is analagous to riding a bike. However when you build a significant piece of software this is a tiny part of the problem. You also need to understand the domain of the problem, any other systems or libraries that you need to use, how to structure a sensible solution, the time and space constraints and characteristics of your system and a whole load of other things. If you get any of these conceptually unrelated things wrong then your system is likely to fail completely. It's very difficult to "go slowly" or "get off and walk" as you would on a bike.

But it's more different than that.

The idea of studying computer science at university is not to teach you to write good programs in Java or C++ (or whatever). This should not be a surprise, but I fear that it will be for many students. The idea of studying computer science at university is to develop a sufficiently good understanding of the fundamental issues of computer science that you can understand, analyse, predict the behaviour of and create computer systems in a wide variety of settings and applications. The idea is to equip you with the intellectual tools to allow you to tackle a wide range of problems in computing. The precise set of intellectual tools that we aim to provide depends on what degree scheme you are on. A happy outcome of acquiring this set of intellectual tools happens to be that it will make it possible for you to relatively easily learn any of the huge variety of programming languages that are out there and to write good programs in them.

The process of trying to help students to acquire a set of intellectual tools appropriate for any discipline, whether it be history, French, philosophy or whatever, is fraught with many dangers and difficulties. Computer science is particularly fraught because it is such a young university subject: no-one can really agree on much about how it should be taught or even what the essential intellectual skills are. Whilst philosophers are an argumentative bunch, I suspect that most of them would be able to agree that there are some really fundamental ideas at the heart of their topic and some really well rehearsed arguments about them that any philosophy student should study, maybe something like the nature of knowledge (epistemology) would be considered to be one of these fundamentals. Computer scientists can't even agree on whether or not, and certainly not how, we should teach programming (yes there have been very good computer science courses that didn't teach programming).

So whether you like it or not, computer science students are guinea pigs. Philosophers have had a few thousand years to figure out where some of their priorities lie, maybe in a few hundred years we'll have some better understanding of what computer science is all about.

In the meantime we are trying to teach people using whatever ideas and tricks that we can. For example in my ubiquitous computing module I regularly set an impossible problem in order to get people to think through possible technical solutions to parts of the problem. Not because I expect them to solve it, but because I want them to think through a difficult problem in a scenario with which they are not familiar. I want them to got through the process of assessing which parts of it they think they can tackle, and to use the intellectual tools they have acquired in this module and all the other modules that they may have sat to create potential solutions to parts of the problem. For me this process of understanding an application area outside computer science and developing sufficient understanding of it such that you can create solutions in that area is at the heart of ubiquitous computing. That is one of the "tools" (probably the most generic one) that I would like people to take away from this module: the idea that you have to study and think about the scenario which you are tackling in order to produce effective solutions. I don't really care about what the particular scenario is, but I do care that people go through the process of understanding it, thinking about it and finding technical solutions that fit into it. Because that is the kind of skill that will be useful for them in this area in future.

This is where the difficult learning bit comes in. Unfortunately you have to trust us when we tell you that this stuff is "good for you". Even if you don't believe the rationale that we give you for trying to solve an impossible task. It really does seem to work. Honestly it does. But it does involve some seriously hard work to do this sort of thing, both in terms of reading, thinking and investigating, but also in looking beyond your immediate boundaries. Having said that, we have only had a few decades to try to get computer science teaching to work, and in the case of something like ubiquitous computing even less. We (at least I) do get things wrong, but I really do believe that we need to concentrate on things that are more fundamental than just how to write good Java or C++. I think teaching you to write good Java or C++ can be a useful exercise, but trying to help you keep your eye on the bigger issues is also very important, and I for one will keep trying to help students to think beyond the obvious and immediate. I also think that that is what good employers want. If they want you to write Java or C++ then so be it, but they will also want you to be well-informed enough to understand the pros and cons of various approaches and to be able to understand and work with experts in other fields.

In short, I think that you do need to "get your head down" and tackle the tasks you are set, but that the really useful learning is in the time after you have done the assignment or sat the exam when you sit back and think "Ah, so that was what that was all about!".