Defeating Mr CO2 book extract: an excerpt

Last week, Ashak Nathwani launched his book Defeating Mr Co2, which saw the attendance of many notable figures in the industry, such as former GPT head of office Tony Cope and Stephen Ballesty. Read more about the launch and what they said here. Below is an extract from Nathwani’s book.

Cost of living – savings

This chapter is about reducing energy bills in the home. There are steps that each one of us can take to reduce our carbon footprint by saving energy—and save money, too!

We consume energy for lighting, powering appliances, maintaining comfort, and cooking. Energy can take various forms, such as electricity, gas, diesel, wood, coal, and petrol. Factors influencing energy consumption include lifestyle and affordability of energy consuming equipment.

Typical energy break up of energy consuming items:

There are great variations in energy consumption of different types of dwellings. Overall design and orientation of the house (e.g. window placement for natural lighting) affect energy needs. Larger homes require more energy for heating, cooling, and lighting. Open floor plans may result in higher energy usage, too, due to the need to maintain consistent temperatures across larger spaces. Homes in extreme climates (hot or cold) typically consume more energy for heating or cooling. Seasonal changes also lead to fluctuating energy use. Materials like brick, stone, or energy efficient windows do help in reducing energy loss.

Reducing energy in the home

Regardless, there are a few common approaches when it comes to implementing energy reductions.

• Select energy efficient appliances such as refrigerators, washing machines, dishwashers, and televisions, designed to consume less electricity while performing their functions effectively. The Energy Star system can help you understand the energy use and running costs of household appliances. Look at the energy rating label. The higher the rating, the more efficient the product.
• Replace traditional incandescent bulbs with energy-efficient LED lights, which consume significantly less energy and have a longer lifespan.
• Improve insulation in walls, floors, and ceilings to minimise heat loss during winter and heat gain during summer, reducing the need for heating and cooling.
• Install energy efficient windows with low-emissivity coatings and insulated frames to reduce heat transfer and improve thermal performance.
• Curtains, on average, reduce home energy bills by around 7 per cent in warmer months and 9 per cent during colder months. During colder months, it is important for the curtains to be open during the day to benefit from the winter sun (based on appropriate orientation) but closed at night. As stated before, this creates a “blanketing effect” to keep the warmth in and the cold out.
• Seal gaps and cracks around windows, doors, and other openings to prevent air leaks, which can result in energy loss and increased heating or cooling demands. Draft stoppers at all external doors, on average, reduce energy bills by 5 per cent, depending on climatic influences and the extent of infiltration.
• Natural ventilation strategies, such as opening windows and using ceiling fans to circulate air, maintain comfortable indoor temperatures without relying solely on mechanical cooling systems.
• Energy efficient HVAC (heating, ventilation, and air conditioning) systems, including high efficiency heat pumps and air conditioners, use less energy than conventional systems while maintaining indoor comfort.
• Install programmable or smart thermostats to regulate heating and cooling systems efficiently. These thermostats adjust temperatures based on occupancy and time of day to reduce energy waste.
• Encourage energy-saving habits among household members, such as turning off lights and unplugging electronics when not in use, using appliances efficiently, and setting thermostat temperatures wisely.
• External shading can reduce energy use by up to 50 per cent. Shading devices can be fixed or roll down awnings. Better still, if land is available, plant appropriate trees that could provide shade. These have the added benefit of absorbing CO₂, thereby reducing GHG emissions even further.

Implementing these energy saving measures can significantly minimise energy consumption, lower utility bills, and contribute to a more sustainable environment through reduced GHG emissions.

The electric kettle 

Let’s take a kettle, for example. If a kettle heats one cup of water to 100⁰C four times a day for a year, it will consume 81.7 kilowatt-hour of energy a year. This equates to 0.06 tons of GHG emissions and 2 trees worth of CO₂. If only one cup of water is needed, but that kettle is filled up to capacity, it is heating six cups of water every time it is used. In that scenario, the energy consumption yearly is 258.5 kWh – equating to 0.24 tons of GHG emissions. Heating a whole kettle when you only need one cup leads to a whopping 216 per cent increase in energy usage and GHG emissions yearly! However, if the temperature is set to 80⁰C instead of 100⁰C, you cut your energy usage by 24 per cent. Consider this the next time you have a cuppa.

I have done the maths to quantify simple ways to save energy to enable individuals to make informed decisions.

Refrigerator

Every time we open the refrigerator door, we are adding heat into the refrigerator. That refrigerator will then work overtime to cool down. This means that the energy-consuming compressor operates for a longer period. If over twelve hours, you open the fridge every hour, compared to three times an hour, you can reduce your energy usage by around 24 per cent a year. The longer the door is open, the higher the energy wastage. The door alarm is a good quasi-energy-saving device but be mindful and do not wait for the door alarm to tell you to save energy by shutting the door.

Following is an analysis carried out:

There must always be adequate air space around the refrigerator, especially around the back and the top. This is because, as you will recall, the refrigeration principle is based on energy transference between the inside and the outside. Any heat build up at the rear side of the refrigerator impacts refrigerator efficiency. Additionally, ensure the door seals are airtight to prevent heat ingress.

Washing machine & clothes drier

Goes without saying that the appropriate loading selection features of both the washing machine and the clothes drier need to be utilised for the tasks at hand. The power consumption of a clothes washing machine can vary depending on factors like the model, washing cycle, and water temperature. However, the difference between a fully loaded and half loaded machine primarily depends on how the machine handles the load size. Many modern washing machines have sensors that adjust the water level and cycle duration based on the load size. In these machines, power consumption for a half load is typically less than for a full load because the machine uses less water, and the motor operates for a shorter duration. Since power savings are not proportional, running the machine with a half load often leads to higher energy consumption per kilogram of laundry. For example, if a full load consumes 1 kWh, a half load might consume around 0.7 to 0.8 kWh, not exactly half.

Older machines that do not adjust based on load size will consume almost the same amount of power regardless of whether they are fully loaded or half loaded. This is because the machine uses the same amount of water, and the motor runs for the same duration regardless of load size. Hence, the golden rule remains that a full load of washing is generally more energy efficient per unit of laundry.

How does the operating power compare to the published power rating of the machine?

The power usage varies during different cycles, such as washing and spinning cycles. Evaluation carried out on the washing machine shows the following:

Clothes washing is carried out during sunlight hours to take advantage of the free solar energy. Hence equivalent number of trees shown above are “virtual trees” planted.

We only use the clothes dryer on rainy days. Like the washing machine, the clothes dryer’s power consumption varies depending on the load.

Tests carried out of the clothes drier show the following:

To dry our clothes, we use the famous Australian Hills Hoist—a great example of the combination of solar and wind energies. Amazingly, the Hills Hoist has not gained international popularity. I have not seen it being used much elsewhere in the world.

Based on the calculations, the use of the Hoist has resulted in a saving of around $249 per annum in our estimate.

Net zero and electrification

This resonates with the principle that I advocate for attaining net zero for existing buildings. We need to focus on reducing energy consumption and transitioning to renewable energy sources. This could be by retrofitting older buildings with new technologies, improving insulation, encouraging occupant behavioural change, and installing renewable energy systems like solar panels or hydrogen powered generators to provide clean energy.

Cooking associated data

Gas is the most common utility used for cooking. Wood is still used as fuel in developing countries. For a building to attain net zero carbon, all fossil fuel based cooking items, hot water and standby power generation equipment need to be upgraded to be electric. This part of the electrification process is being encouraged universally.

Case study – high cost – gas to electric cooking stoves  

There is a relatively high contribution to GHG emissions from the gas cooking stoves. They need to be replaced with electrical stoves and an appropriate number of solar panels must be installed to provide electricity via a renewable source.

ECM 3 (HIGH COST)	No. of New Electric Stoves	Energy Saving (kWh)	GHG Reduction (Tons)	Equivalent Trees Planted	Investment Cost (PKR)	Cost Saving (PKR)	Simple Pay Back (Years)	Simple ROI (%)
Gas to Electric Cooking Stoves	2	16,640	6.2	246	7,234,240	848,640	8.5	12%

Shade and solar

“Shade and solar” is a new technology that provides appropriate external shading (with suitably spaced panels to meet indoor daylight requirements) and, at the same time, each shading panel has photovoltaics able to generate around 80 watts (peak) of electricity. They can be retrofitted in existing buildings.

The panels rotate following sun angles (using AI-based pneumatic controls) to achieve maximum shade and solar energy. The provider is Solskin – a firm based in Zurich, Switzerland. I visited the factory in April 2024 and conducted further evaluations concerning available maintenance and support in developing countries. The firm is in the process of arranging support in various countries.