Back to (solar) school

Some lucky students in Canberra won’t just be hitting the books when they head back to school next week – they will also become junior CSIRO scientists, helping us with our solar research.

Solar research stations have been set up in four Canberra schools to help CSIRO study the output of photovoltaic (PV) panels. The data will help us to predict the behaviour of PV panels in urban areas and could help future power supply planning.

The school’s PV panels are connected to a website where the data can be monitored in real-time.

More schools will join the research program this year!

It’s real-time learning! Have a look for yourself at: weru.csiro.au or watch the short ABC News video below showing the research in action.

A screen grab of the WERU website data.

An example of the data from the rooftop installation.


100th blog post

The CSIRO Solar blog has made it to 100 posts, and we’ve celebrated it by doing what we do best: harvesting power from the sun.

Photovoltaics research scientist Greg Wilson fabricated this dye sensitised solar cell in CSIRO’s Newcastle lab and I think you’ll agree it’s a pretty great way to commemorate our achievement and show off the technology at the same time.

Click through the pictures below for more details of the fabrication process.

We plan to show you this process in more detail in future posts of the blog.

We’ll also be posting ‘100 facts about solar at CSIRO’ over these next few weeks, so keep an eye out for them.


CSIRO report finds solar intermittency can be managed

It’s no secret that solar energy can be an intermittent power supply. Passing clouds can cast shadows on solar generators, interrupting a steady supply of electricity to the grid.

So what happens as Australia builds more and more solar power stations? It’s important to know whether we can maintain a stable and reliable grid despite the intermittent nature of renewable technologies.

A new CSIRO report, released today, opens with a statement setting the scene:

Whilst much is said about the effect of intermittency on electricity networks, the information shared and views expressed are often anecdotal, difficult to verify and limited to a particular technical, geographical or social context. There is surprisingly very little real-world data on how intermittency, particularly solar intermittency, affects electricity networks.

This report, entitled Solar intermittency: Australia’s clean energy challenge, is a first step toward filling this gap in our knowledge. It’s the result of a 12-month study by CSIRO, the Energy Networks Association (ENA), and Australian Energy Market Operator (AEMO) into solar intermittency. It provides an analysis of worldwide research, examining what conclusions can be drawn and applied to the Australian context. Funding was provided by the Australian Solar Institute (ASI). You can read more about the research, its findings, and our partners here.

One key finding is that solar intermittency can be managed. Important steps on the path to achieving this will include having access to accurate solar forecasting, and being able to carry out further research and demonstration studies in Australia.

Click here to download the full report (PDF, 6 MB).

Lead author Saad Sayeef spoke to Solar@CSIRO about the report, its findings, and future research. Click the video below (2:07 min) to watch.


Positive Impact

From keeping flies off Her Majesty, through to inventing the Wi-Fi technology that lets you surf the web on the train: CSIRO has been an agent of positive impact for over 80 years.

Check out CSIRO’s new video above, and keep your eyes peeled for the feature appearances of our solar field.


A flexy flyer for download

For the Questacon school careers expo this week we wanted to publicise the solar blog. Leaflets or postcards seemed a bit boring though. So instead, this was what we came up with: a CSIRO Solar Blog Hexaflexagon.

Our hexaflexagon is a seemingly flat, two-sided shape that turns inside out to reveal three separate faces. Not only that, each face can rearrange itself in two different patterns. The shape and its variants have a good science pedigree, too, with people like Nobel physicist Richard Feynman and ‘mathemagician’ Martin Gardner part of its history.

Click here to download a PDF copy you can print and fold yourself. All you need is some scissors and glue or double-sided tape. Instructions are included on the sheet.

Warning: the flexing of a hexaflexagon can become compulsive behaviour. Have fun!


Saving energy on site, part 5

Messing with our heads… in a good way

This post is part of a series on CSIRO Newcastle’s energy-efficient office buildings. Read all the posts in the series here.

Are you reading this in an office building right now? If so, how’s the temperature? Is the air-conditioning turned up too far or down too low? Are you too cold or too hot? If so, research has shown something surprising: you might be happier if there was no air-conditioning at all – even if it makes the room even colder or hotter than the temperature you’re uncomfortable with right now.

To explain this crazy-sounding result we need to go back to some research that started in the 1980s, and led to some findings that influenced the design of the CSIRO office building that I’m sitting in at the moment.

In the mid-1980s, researchers in the American Society of Heating, Refrigerating and Air Conditioning Engineers (ASHRAE) began to fund some studies into building temperature and comfort. They were interested to find out what range of temperatures people found too hot, too cold and just right – and how it varied with things like season and climate. With this data, people designing new buildings would have a better understanding of what sort of air conditioning or heating systems they’d need in order to keep most people comfortable and happy. (Note: it’s widely recognised that you can never make everyone happy with the indoor temperature. That’s why building standards generally consider an 80% satisfaction rate to be perfectly acceptable.)

One decade and several additional studies later, ASHRAE had collected around 21,000 sets of data from 160 different office buildings. This included locations over 4 continents, spanning climates from tropical Singapore to sub-arctic Canada. With all this data it became possible to work out a nice equation into which you could feed information about the outdoor temperature, indoor air speed, humidity, metabolic rate and even the sort of clothing people wore inside, and it’d tell you where to set the air-con to make most people happy.

This equation was pretty accurate for most standard air-conditioned offices, which you can see from the image below. If the scientists knew what they were talking about, the thick black line, showing the predictions given by the equation, should match up with the lighter line with white squares, which shows the office temperature people were actually most happy with. As you can see, it’s almost a perfect match. Equations predicted a narrow ‘Goldilocks’ window from 22.5 to 24°C where people would feel not too cold or too hot, but just right – and this is exactly how people behaved (on average) in real life.

Predicted and observed ‘comfortable’ indoor temperatures for air-conditioned office buildings. From de Dear & Brager, 2002.

But something really weird happened when researchers tried to apply the same equations to buildings that didn’t have air-conditioners; buildings in which if people were hot or cold they’d simply open or shut their windows. For these buildings, the wheels fell off, and the equation – which included every factor scientists knew of that influenced thermal comfort levels – couldn’t account for what was being observed. People were, in fact, much more tolerant of higher and lower temperatures than was predicted.

Predicted and observed ‘comfortable’ indoor temperatures for naturally-ventilated offices. (From de Dear & Brager, 2002.)

In short, there seemed to be something mysterious about air that came through an open window that made it better. Natural air seemed comfortable from about 20 C (on freezing cold days) right up to 27 C (on searing hot days), but take the exact same air and deliver it through an air conditioner, and people would generally find it several degrees too hot or too cold.

Clearly, something else was going on that scientists didn’t understand. But Richard de Dear from Macquarie University in Sydney and Gail Brager from University of California, Berkeley had a hypothesis. They proposed that the difference was mainly psychological.

They believed the differences arose partly because people are more tolerant of situations they can control (like being able to open a window) than those they can’t (such as when someone else has set the air-conditioning, and there’s nothing you can do about it!). They also hypothesised that people get used to the narrow temperature variations of air-conditioned buildings, and that this in turn makes them less agreeable to further variation. If you can open a window on a hot day, on the other hand, a hotter office feels more ‘natural’, and likewise for a cold office on cold days. For more information about de Dear and Brager’s work, see this paper from which the above graphs are also taken.

This hypothesis has been fairly well substantiated over the years, and it goes a fair way towards understanding why, when our building has so many smart energy-saving gizmos with computer control, the architects chose to give us windows that could be opened manually. While the temperature control might be more precise if a computer decided when to open and shut them, it turns out people are much less fussy about temperature if they are simply given the ability to open and shut their own windows.

In reality, our building engineers have gone a step further and combined the two. We have manually-opening windows and a computer system that suggests, by changing the colour of an icon in our system tray, when it might be best to have them open and shut.

A colour-coded icon in our system tray tells us when to open our windows (green), keep them closed (blue) or try and reduce energy usage during critical peak periods (red).

Importantly, too, the computer system also accepts feedback from users, who can send instantaneous comfort reports saying if they’re too hot or cold. The computer knows which zone of the building the feedback’s coming from, and takes into account all the feedback to adjust the temperature setting or ventilation mode. All this gives people more control over their environment and increases the chances we’ll feel comfortable.

The electronic comfort survey in our building. If people are feeling uncomfortable, the temperature set-point or ventilation mode is automatically changed.

What’s the message from all this? In a society where buildings account for 20% of all energy usage, and air-conditioning accounts for the largest portion of this, we might be able to use far less energy – and be even more comfortable – if we turn our air conditioning off from time to time and throw open the windows instead.

◊  ◊  ◊

This is the last post in the series I’ve been doing on the energy-efficiency features of our buildings at CSIRO in Newcastle. As you can imagine, what I’ve put here on the blog only scratches the surface. If you’re interested in reading about our building in more depth I’ve uploaded some recent conference papers by our building engineers on the site’s recent performance and on-going improvements:

And finally, you can see a video below that summarises most of what I’ve written about recently. It’s a few years old now but most of the details are still correct.

Remember, too, that Earth Hour is coming up on the last day of March. It’s a chance to take stock of how much electricity you use in your house – and how much of that you could do without. Perhaps the information in the last few posts has given you food for thought about energy reduction and some ideas for your own place. If so, or if you have other energy-reduction strategies that have worked for you, leave a comment and tell us about it!


SolarGas Part 1: What it’s all about

It’s a clear spring day in this photo of Solar Field 1 at our Newcastle site. There’s obviously plenty of sunshine to power solar panels or solar turbines. But in this case there’s more going on than meets the eye. Even after the sun has set we’ll still have a supply of solar energy, thanks to what’s in the small shed circled below.

In the shed is a group of gas cylinders. They’re holding the product of a process that CSIRO has developed to near commercial demonstration that captures and stores solar energy for later use. Because the added solar energy is stored in the chemical bonds of a gas, we call the product SolarGas™.

SolarGas isn’t just a way of storing solar energy. It’s also a way to add solar energy to fuels like natural gas, and it can even be used in production of many liquid fuels and fine chemicals which currently rely on finite fossil fuel feedstocks. It’s been one of the main areas of research and development for our solar thermal team over the last decade, and that’s because we think it’s a really versatile product that’s well suited for Australian resources and needs.

I get asked questions about SolarGas all the time from people ranging from school students to scientists. For people who don’t work in process industries (that’s most of you, I’m guessing) I’ve realised that to really get across why SolarGas has so much potential, it’s necessary to take a bit of time to start at the beginning and explain the concepts involved. Unlike a system that produces electricity – which we can all relate to, because we use it to power our kitchen blenders and so on – SolarGas applications are more varied and perhaps might seem a bit further from home (related more closely to, say, the industrial manufacture of hydrogen rather than lighting our houses at night). Nonetheless, it has the potential to have huge benefits that are worth understanding. That’s why I’ve chosen to spread this article over two sections, and why I’m going to write it for the sort of reader who prefers to call a fire ‘hot’ rather than ‘exothermic’. No apologies.

How it’s made

To make SolarGas, we use mirrors to focus solar energy onto a series of metal pipes, which creates temperatures of around 800°C inside them. Through these pipes we flow a stream of natural gas mixed with something else. This ‘something else’ can be steam or carbon dioxide – both pretty common ingredients, suited to different situations.

These metal pipes form our SolarGas Reactor, and they have been carefully designed so that inside them the conditions are right for a chemical reaction to occur. This reaction converts the natural gas and steam (or carbon dioxide) to a new mix of gases, and in the process ‘sucks up’ a whole lot of solar energy into the new gas molecules in what is called an endothermic reaction. If you could touch the pipes where the reaction is going on (and we wouldn’t recommend it)  you’d feel that they’re actually cooled as energy transfers from solar heat to chemical bonds – thus changing it into a form that, unlike the energy in sunlight, can be stored in bottles or pumped from place to place.

It’s interesting to note that steam and carbon dioxide are the products of normal combustion. So here, where we’re using them as the reactants, we’re in essence turning the usual reaction around using energy from the sun. That’s neat.

So, the result is that we’ve produced a new gas that has more energy than the gas we started with – and this extra energy came from the sun. The video below gives an overview of the process. In this example, the more common steam version of the reaction is shown.

You might have noticed that the video shows what SolarGas is. It’s made up of hydrogen and carbon monoxide – specifically, three units of hydrogen gas for every molecule of carbon monoxide gas. This mixture makes the gas very useful in a number of ways.

But that’s a topic that deserves a post of its own. Next: Part II – how it can be used.