Posts Tagged ‘IB Environmental Systems & Societies’
Solar Developments in the OSC Neighborhood
DP2 Environmental Systems & Societies students experimenting with a 15 W PV panel.
Like other parts of the planet there are significant developments in solar energy generation in Sri Lanka. The costs of photovoltaic (PV) panels have come down and net metering allows small operators to export their power to the grid built and maintained by the Ceylon Electricity Board. After many years of reading about the solar revolution it has been thrilling to have a colleague install a system at her house. Encouraged by these developments, OSC’s DP Environmental Systems and Societies (ES&S) students are investigating the basics of PV-generated energy. It has given me a chance to brush up on power and energy concepts as are applicable when talking about the generation of renewable energy.
My personal interest in energy goes back to my father Merrick Lockwood who has been working with alternative energy projects since the late 1970s. His significant work was on a biomass-fueled Stirling cycle engine that produced power to run a rice mill. You can about the joys and tribulations of his work in Bangladesh in How I Built a 5HP Stirling Engine (it is an intriguing account narrating the Rice Husk Energy project though the title was not Merrick’s choice). Stirling engines were a major focus point but Merrick has always been interested in an array of conventional and non-conventional energy technologies. I have strong childhood memories of PV cells, batteries, meters and literature on renewable energy in the wonderful clutter of his office and workshop. Earlier this year my alma mater KIS installed a 2 kw set of panels though the tireless work of Class of 1952 alum Dr. Clarence Maloney. His efforts helped get me thinking about solar energy as a viable option.
Sri Lanka sits in an enviable location to tap into renewable energy. Because it is so close to the equator (6°-9.5° N) it is bathed in insolation (solar irradiance) throughout the year. Sri Lanka is blessed with high rainfall in its “wet zone” and here it taps into large and medium-sized hydroelectric schemes which generate about half of all the electricity use in a year. Sri Lanka’s coastal areas offer great potential for wind power generation (something being explored in the Kalpitiya region). Biomass fuel provides for much of the country’s cooking needs in rural areas and if managed correctly can be a sustainable energy source. At the moment Sri Lanka’s electricity demand is growing and it gets significant power (up to 40-45%) from thermal plants burning heavy oil and coal. The chart below shows the source of electricity on 16th November 2015. Because of the high rainfall in the catchment areas there is optimal hydroelectric production (68% of the total).
This chart shows the source of Sri Lanka’s electricity on 16th November 2015. Because of the high rainfall in the catchment areas there is optimal hydroelectric production (68% of the total).(CEB)
The catalysis for my current interest interest in solar energy at OSC was my colleague’s Chamilla Ratnaweera decision to install an array of PV panels on her rooftop in July this year. She and her husband have sixteen 0.46 m2 panels for a total of 23.36 m2. They have a net-metering arrangement, which means the power that they generate goes straight into the grid and runs their meter backwards (“exporting” units on their bill). When they draw power (it is mostly at night and on weekends) the system takes electricity from the grid. Not having batteries and having to deal with the storage of solar generated electricity simplifies the process in net metering. It assumes, of course, that there is functioning electricity grid.
In September Chamilla’s panels produced an average of 14.3 kWh of solar energy every day (see graph below) and they have not paid an electric bill for the last three months! What is even more remarkable is that have also purchased a Nissan Leaf eclectic car and are able to charge the vehicle and meet their electrical energy requirements with their panels! Chamilla has access to daily, monthly and yearly data on solar energy generated (in kWh). There are several companies offering schemes and they purchased their set up through Solar Edge (marketed here by JLanka Technologies). According to their company literature a similar set with installation costs roughly LKR 1.1 million (US$ 7,700). Our class has been checking on her daily power generation every day for the last two weeks.
Graphs showing solar production in kWh generated at Chamilla’s home in September and October 2015. Even though these were relatively wet months the system generated 430.4 kWh in September and 468.87 kWh in October.
As a part of this study I visited the Sri Lanka Department of Meteorology on November 6th. On this initial trip I had several interesting discussions with the meteorologists who run operations and I was also able to purchase solar radiance and rainfall data. The graphs below chart solar radiance (in MJ/m2/day) against the solar energy generated by Chamilla’s panels (in kWh/day). Other than the days where there was maintenance on the panels there is a clear pattern between radiance and solar energy generated as one would expect.
Chart showing solar energy generated vs. solar radiance as recorded by the Sri Lanka Meteorology Department. Noe that at the beginning of the month the panels were not running at their full potential. They were serviced on September 22nd and 25th. There is 5-10 km between the two locations where the data was recorded, which may partly explain discrepancies.
Chart showing solar energy generated vs. solar radiance as recorded by the Sri Lanka Meteorology Department for the month of October. Like the graph above the energy generated follows the pattern of the solar radiance. The data from October 9th and 27th was originally missing and I have substituted near values.
To better understand solar energy the class tested a small 31 x 37 cm 15w panel that the Physics class purchased last year. Will Duncan, the Head of Science, gave me a primer and demonstration on how to rig up the voltage and current meters and make calculations on energy generated by the panel. We are using Vernier’s Labquest2 devices and these are versatile data loggers that allow students to gather raw data from a variety of probes. This year we purchased the pyranometer probe, which measures irradiance (in w/m2) and allows you to then calculate the efficiency of solar panels. I ran trials with the Labquest simultaneously taking in data from three probes (voltage, current and irradiance). The raw data is then imported into Loggerpro where power and efficiency is graphed and analyzed.
Measuring electromagnetic radiation (irradiance) (in w/m2) over the course of the day in our Colombo neighborhood. The results are given below.
Graph showing irradiance data gathered over a 12 hour period at our home in Battaramulla on November 7 2015. The Labquest2 with the pyranometer gathered data every minutes for 12 hours (720 minutes).
Map showing annual irradiation (radiance) levels in kWh/m2 draped over an elevation model (sourced from the amazing website SolarGIS). Both Sri Lanka and southern India have optimal conditions to tap into solar energy!
Weather is obviously a major factor in producing solar energy. We have just experienced unseasonably wet months in September and October. In fact his last Sunday- an overcast, gloomy day that experienced rainfall for much of the day- Chamilla’s panels generated 6.89 kWh of solar energy! That is lower than the 14.34 kWh September average but still significant. We have not yet done a full cost benefit analysis of the panels but it is quite clear that they pay for themselves quickly. If the electricity bill was roughly LKR 25,000 a month, the system would pay for itself in under four years. The company, like many here in Sri Lanka, is advertising the system to have a 25 year lifespan. If you are a house owner or run a large institution, such as a school like OSC, investing in a PV systems makes both sense for the climate and your wallet.
Sun or shine, there are ample opportunities to generate solar energy on OSC’s many roofs. With net metering the school could potentially offset its high monthly bills.
In the next post I’ll explore rainfall data in these last few months in order look at patterns and changes from past years.
REFERENCES
Biello, David. “Less polluting energy sources are proliferating in the U.S. If other nations join in, the results could have global impact.” Scientific American. 18 November 2015. Web. 24 November 2015.
Jayawardena, Dulip. “Potential for renewable energy in Sri Lanka.” Sunday Times. 31 October 2010. Web. 14 November 2015.
NASA. Global Maps: Net Radiation. Web. 17 November 2015.
NASA. Net Radiation (1 Month). Web Data Portal. 17 November 2015.
Plank, Alexandria R. et al. Renewable Energy With Vernier. Vernier, 2012. Print & Web.
Renné, Dave et al. Solar Resource Assessment for Sri Lanka and Maldives. Boulder, CO: National Renewable Energy Laboratory, 2003. Web. 14 November 2015.
Renewable Energy for Rural Economic Development Project-Sri Lanka. Web. 13 November 2015.
Rodrigo, Chatura. “The Road to Becoming an Energy Independent Country: Can We Deliver?” Talking Economics. 5 August 2015. Web.
Solar GIS. Irradiance Portal. Web. 14 November 2015.
Sri Lanka Sustainable Development Authority. Solar Resource Atlas of Sri Lanka. Web. 14 November 2015.
Sri Lanka Sustainable Development Authority. Sri Lanka Energy Balance 2007: An Analysis of Energy Sector Performance. Web. 14 November 2015.
Solid Waste Reduction Initiatives: The City, the School and the Home
Compost at three stages in our garden. The Vernier Labquest shows the temperature of each bin. The active bin and temperature is on the left with a temperature of 47.1 C showing healthy levels of metabolic activity.
One of my struggles as a human being living in a 21st Century industrial, consumer-driven society is how to better live up to the ideals that are imbedded in the concepts that are a part of the course content that I teach. The IBDP Environmental Systems & Societies course promotes ideas of sustainability (defined roughly as the extent to which natural income is utilized without affecting the natural capital of a system). IBDP Geography also looks at sustainability but spend time on populations, resources and the broad concept of carrying capacity. In the IBDP Creativity Action & Service (CAS) course outline the issue of “considering ethical implications” of one’s actions are highlighted in the eight IB learning outcomes. One contemporary environmental challenge that I have made efforts to address since my days as an undergraduate student is the issue of solid waste. I see our home as a virtual laboratory to test just how much we can cut back and reduce our family’s ecological footprint. In this post I’ll review the recycling and solid waste situation at three different scales here in Sri Lanka.
THE CITY
Colombo faces significant solid waste challenges as it experiences rapid growth in the post conflict years. The problem is not so much one of human numbers but of human lifestyles with per capita consumption and solid waste generation going up. Local newspapers (see References below) highlight problems with disposal, tension in communities stuck with city waste and controversial plans to incinerate waste. Approaches to recycling have changes during the last 10 years that we have been living in Colombo. In 2006-7 the Colombo Municipal Council set up several eco-kiosks for consumers to drop off recyclables at. It was a nice idea, but from my observations and interactions, the eco-kiosks had a mixed rate of success. Some discerning citizens used them regularly and deposited loads of cleaned recyclable materials. However others treated them as places to toss unsorted waste. Without proper supervision, the two eco-kiosks in our area (Talawathagoda and Battaramulla) became foul-smelling, cluttered sites that few people wanted to use. They were closed down two years ago. Most households now rely on a municipal neighborhood solid waste collection service that comes by with a tractor and trailer every week. Households are requested to sort their waste into two broad categories (organic and non-biodegradable items). The municipal workers sort the waste into organic and non-biodegradable sections (see image above). Their tools are basic and they endure unsavory working conditions. Unfortunately these hard working teams are unrecognized for the key role that they play in the city’s environment. The waste is carted off to one of several sites where it might be further sorted and then is basically left to rot, with some of it being burnt. It is this reality that has been the subject of concern amongst citizens and environmentalists in the city.
Haphazard solid waste disposal and burning behind a major grocery store chain in the Pelawatte/Thalawathgoda neighborhood. The practice of burning waste, which often includes significant amounts of plastic and other synthetic materials, is widespread.
For a variety of reasons there is a high prevalence of small-scale waste burning in Colombo’s residential neighborhoods. Traditionally people must have lit small fires of leaf litter and other collected waste that is swept up at the end of the day. In our area (that falls under the Battaramulla municipality) many neighbors continue to burn mixed waste. One neighbor suggested that the burning is timed to suppress mosquitos. The problem is that now household produce a good deal of waste that is synthetic and this gets thrown on to these same fires. There are few days that we don’t pass by a fire with burning plastic, PVC, styrofoam and any number of other items. This obviously has serious health consequences.
How domestic solid waste is collected from our home in Pelawatte, Sri Lanka.
THE SCHOOL
OSC with its 500 + students, teachers, administrators and support staff produces a significant amount of solid waste that is collected by the Battaramulla municipal council teams. There is some sorting at the cafeteria where wet waste is partially separated from all other kinds. The OSC Recycling and Sustainability (R&S) project has a mission to reduce the volume of solid waste and raise awareness about environmental and sustainability issues on campus. The group has a stated goal of reducing the school’s ecological footprint. Its weekly activity consists of collecting recyclables from classrooms and offices. The recyclables are sorted and the data is recorded with the idea of studying long-term trends to see if the efforts to reduce are having any impact. The group also works on projects with the canteen and administration to reduce waste at source and promote energy conservation. Over the years we have had several notable and energetic student leaders including Olivia Molden, Yi Suel Shin, Yulia Alex Mylvaganam, Satyanshu Sapra, Jennifer Anderson, Constance Klemplin, Yoon Jae Hwang, Nishant Matthews and several others. See the blog link here and below to get a sense of what the group has done in the last five years (the blog was started in 2010-11). Environmental issues also figure in course content in all three IB programs. The Primary School is very good about raising awareness about issues and the Middle Years Program (MYP) does studies on energy and ecological footprints. In the Diploma Program the Geography class uses the issue of solid waste and recycling to run field studies and surveys. This is shared with the wider OSC community through the weekly newsletter and R&S blog.
OSC recycling in action (from the top): Students in the Thursday afternoon R&S service activity collect and sort paper, cardboard and other materials outside the recycling room near the gym. DP Geography students weigh and sell cardboard to our main scrap dealer buyer who will resell it for recycling in India. DP R&S student leaders Nisala, Nandini and Nishant work with younger students on a reflection at the end of the Thursday service session. Data about patterns in consumption and recycling is gathered and analyzed as a key part of this activity.
THE HOME
It must have been was growing up in Bangladesh where I learnt that there is no such thing as garbage; only resources. Nothing went to waste in Dhaka, from empty beer cans, to office paper and even plastic bags: all had real economic value that was obvious to most consumers. The key to Dhaka’s successful recycling had little to do with any government planning or fancy development plans. Instead an army of informal workers, each with their own basket and weigh scales, competed to buy, collect and sell whatever they could. Houses in the wealthy neighborhoods of Gulshan and Baridhara were lucrative areas to trawl. High-income lifestyles, especially amongst the foreign community, were relatively wasteful and generated large volumes of perfectly useful materials that could be resold for a decent amount. Extreme poverty helped drive some of this recycling dynamism but the resilience and work ethic of the families collecting and sorting through the materials (often in hazardous conditions) played a key role. Their efforts helped to significantly reduce the need for landfill space, incinerators or other methods traditionally resorted to in industrial societies.
Three stages of compost at home. The bins are made by Arpico and also marketed/promoted by the Sri Lanka Central Environment Authority (CEA).
Living in Pune I was exposed to ideas of composting and vermiculture. Ever since, our family has successfully been able to completely manage all of our own wet organic waste. Here in Colombo we have three bins that have waste being cycled through them. Because of the warm, humid temperatures in Colombo we can recycle most organic waste through the system relatively quickly. It takes about 3 months between the time that a bin is started and then emptied out into the garden. The opening set of pictures shows the temperatures of the three bins. Temperatures are high (@40-41 C°) in the active bin where metabolic activity is high. Then, as the compost breaks down, the temperature drops back down to normal air temperature (26-32 C°) as different organisms works to break down the waste. I’ve learnt to mix an equal amount of leaf litter/grass cutting with food waste in the bins. Any meat waste is kept out and feeds neighborhood dogs and monitor lizards. The plastic of the Arpcio compost containers is hardy and keeps most rodents at bay. I regularly roll the bins on the ground to aerate the compost. I also add a little water to the non-active bins to keep them moist and conducive for decomposers.
This is a rough estimate and breakdown of our household waste in terms of composition and weight (see table below).
In Colombo we generate, what I would assume is, an average amount of solid waste, but based on my research we put out far less garbage than other similar families. Unlike many other houses in the area, our waste (mostly plastic packaging) is not mixed with rotting food (a source of unsanitary conditions and an invitation for stray dogs that like to open bags of mixed waste). Through a combination of active recycling and composting I believe that our household has been able to make major solid waste reductions. At the school and certainly at the city level there is still a great deal more that needs to be done. The issue of dealing with solid waste in a scientific and ecological manner is quite straightforward, while the bigger challenges of the country developing into a resource-consuming society looms with uncertain consequences.
REFERENCES & FURTHER READING
Berenger, Leon. “Garbage Crisis growing by the day.” Sunday Times. 22 March 2009. Web. 23 March 2014.
Central Environmental Authority. Web. {this is the main Sri Lankan government body dealing with solid waste. See Waste Management Unit.}
Dissanayake, Chathuri. “Garbage collection waste deep in management and disposal.” Sunday Times. 15 September 2013. Web.
Ratnayake, Niranjanie. “Issues related to solid waste management in Sri Lanka.” The Daily News. 16 July 2012. Web. 23 March 2014.
Wipulasena, Aanya. “Waste rots, want lots.” Sunday Times. Web.
2013 OSC Field Study to Sri Pada
Collage of snapshots of native flora on the forest trail to Sri Pada’s 2,243 meter summit.
Every December it is my privilege and pleasure to lead a group of DP I (Grade 11) OSC students up the slopes of Sri Pada in order to study the mountain’s ecology and appreciate its value as a stronghold of biodiversity in a rich Sri Lankan cultural landscape. This year I invited the DP Biology class and their teacher Tim Getter to join our group of eleven DP ES&S students. We were supported by our teaching colleagues Sonalee Abeyawardene and Celine Dary (so there were added opportunities to explore ideas of pilgrimages in literature and converse in French during our three days out!). Several students had just completed a heart-pounding SAISA tournament in Muscat and hopped from their airport bus onto ours as we headed up into the Central Highlands on a clear Monday morning.
Vertical zonation studies of floral diversity on the forest path to Sri Pada (center and right) and degraded forest near the Fishing Hut (left). Max, Chadoo and Teresa laying the transect and looking for plant diversity.
The Moray Estate Fishing Hut#1.
ES&S task sheets from the 2013 Sri Pada learning experience.
A contrast in habitats: a monoculture landscape of tea and non-native shade trees overshadowed by undisturbed sub-montane tropical rainforest in the Peak Wilderness area.
Looking for orchids and other delights in the grassy meadow below the peak (altitude 1,900 meters). John visits a favorite, familiar area…
For all students, be they biologists or ecologists in ES&S, the three-day visit to Sri Pada and the Peak Wilderness area offers a unique opportunity to conduct field studies in a biologically rich but anthropogenic influenced landscape. The trip is a unique learning experience, one that is perhaps less appreciated by students in the moment but invariably remembered with great fondness. As usual, we based ourselves at the Moray Estate Fishing Huts. These three rustic cabins are rented out to ecotourists and people willing to put up with simple amenities in order to experience a uniquely beautiful location. Significant time was spent simply getting to the huts and back but once at the Fishing Huts there were all sorts of opportunities for learning. The huts lie at the boundary between manicured tea estates and mid-elevation sub-montane tropical rainforest. This year I highlighted four themes of study for the trip:
- Theme 1: Land Use Variation (anthropocentric vs. natural ecosystems)
- Theme 2: Forest & Vegetation Types
- Theme 3: Vertical Zonation
- Theme 4: Biodiversity in a ‘Biodiversity Hotspot’
Appreciating abiotic factors and the role of decomposers: snapshots from the study on the slopes of Sri Pada.
Our main study day was on Tuesday December 10th (my brother Brian’s birthday!) when the ES&S class ascended the peak. Based on the fitness and gear that the group, I decided to make it a day trip and not spend the night on the top. We went with light packs for the day and were able to conduct a series of line transects as we gained altitude on the peak. The idea was to observe and record changes in plant diversity as we traversed human and natural landscapes and gained altitude on the peak. I had decided to leave my heavy camera gear in Colombo and was armed with a lightweight Canon Powershot, GPS and small temperature probe. The small allowed me to take quick snapshots of the wealth of plant life on the forest trail- and the detail isn’t too bad. Because the hike is physically demanding, there was little time to linger but the group managed at least five transects at different elevations and habitats. We got to the temple around 1:00 –it was pleasantly empty as the season was still a week away from starting. Our lunch of peanut butter and Nutella wraps was shared with a wandering Australian, we rang the temple bells, appreciated the summit temple and then headed back down. One of the students- Max who had been in Muscat playing football for OSC -had a sore knee and we took the last bit slowly. This facilitated a meandering conversation and time to observe the forest much more closely. It was dark by the time we got back to the Fishing Hut.
Snapshots of the OSC Biology class and their teacher Tim Getter in action. On the right, the ES&S class descends from the Peak through sub-montane tropical rainforest.
On the final morning we were able to look at a patch of degraded forest and a eucalyptus plantation. These habitats offer a fascinating contrast to the sub-montane forest. There are numerous invasive species colonizing these disturbed areas but also a gratifying number of native species also making a start. Down below us the biologists completed a biotic index study of two streams (one from the forest and one from the tea estate). We were moving back to Colombo by 10:30 and school wrapped up two days later. Now, as we begin a new term, the classes will be sifting through their data, science journals, photographs and memories to consolidate their learning on Sri Lanka’s sacred mountain.
Past OSC school trips to Sri Pada have been reported in this space:
- OSC Class of 2010 (Sri Pada 2008 trip)
- OSC Class of 2011 (Sri Pada 2009 trip)
- OSC Class of 2012 (Sri Pada 2010 trip)
- OSC Class of 2013 (Sri Pada 2011 trip)
- OSC Class of 2014 (Sri Pada 2012 trip)
OSC’s ES&S students on the last steps and then summit of Sri Pada.
Looking over the Peak Wilderness area to the east and south of the peak from the summit temple. The Fishing Hut and Moray Estate is on the far left.
Scenes from the Sri Pada temple area. This was a week before the pilgrimage season officially opened up and the temple area was serene and quiet.
Sunset over Sri Pada. Taken on Monday December 9th after a cold stream traverse.
