Lecture 7 - Demand side: buildings

Question 1

Which building types consume the most energy (top 5)

Answer 1

1. Retail
2. Education
3. Hotel and catering
4. Warehouses
5. Government

Question 2

What are the key features of UK food retailers?

Answer 2

• V small profit margin (2-6%)
• Account for 19% of UK GHG emissions - supermarkets use 3.5% total electricity (1% GHG emissions), building are v energy intensive.
• Publicise environmental credentials (public cos) - regulation, competition, sustainability strategy (sustainable business model and good PR)

Question 3

Why is there a need to standardise carbon reporting requirements?

Answer 3

• Most reported areas are not the most carbon intensive, e.g. refrigerant not usually disclosed but a big problem, Updated Montreal Protocol for HFCs will have an impact but will take a long time since average life of a fridge is 15-20 years
• KPI reports lack standards and transparency
• Almost no companies publish comparable
• Research suggest that the manage the risk of carbon footprint, a business needs to have: accountability, established KPIs, sustainability reports, low carbon roadmaps

Question 4

What are the key features of supermarket refrigeration systems?

Answer 4

• Chilled: 1-14C
• Frozen: -12- -18C
• Large and constant energy user
• Compressor does most of the work
• System has multiple designs and can run on multiple refrigerants
• A typical supermarket requires 1,400 to 2,300 kg refrigerant - very high GWP therefore serious sustainability issues.
• Multiple trade-offs when deciding which refrigerant to use, e.g. GPW, flammability, toxicity, price, efficiency
• Regulation is pushing towards low CO2 refrigerants

Question 5

What are the key features of supermarket heating, ventilation and air con (HVAC)?

Answer 5

• System relies on: quality of air seal, positive pressurisation, air handling units, temp control
• Put a lot of effort into this - better environment - more likely to return

Question 6

What are the key features of supermarket lighting?

Answer 6

• Goal: illuminate spaces adequately and to enhance shopping experience.
• Usually run on sensors
• Wide range of technologies - florescent, LEDs, dimmable
• Lighting control strategies are coded and uploaded to a programmable logic controller - enhances operation and maximises savings
• Lighting demand (kWh) = (no. of lamps x lamp capacity x no. fittings) + 10% losses

Question 7

What determines refrigerant demand?

Answer 7

• Time of year - highest in summer
• Refrigerant system design
• Age
• Cabinet type
• Refrigerant use rate
• Doors/blinds
• Ambient store temp

Question 8

What are the key challenges to enhancing supermarket building performance?

Answer 8

• Business unaware of their carbon impacts -> growing business therefore more properties with high energy use = unsustainable. Need to future-proof business models.. can they grow without increasing carbon emissions?
• Better building reduce energy requirements and costs
• Need to lose less energy and source products sustainably without impacting customers
• Risk of greenwashing - light green = pay someone else to decarbonise operations, e.g. purchase renewable energy, vs dark green = decarbonise operations yourself, e.g. install your own solar panels
• If the corporate mindset is right, the steps to a sustainable business model are: (i) Account performance - benchmark performance, monitoring, metering and analytics (ii) Identify cost effective mitigation alternatives, e.g. energy efficiencies, design spec, low carbon tech, project manage, implement and validate initiatives

Question 9

What factors influence energy decision making?

Answer 9

• Policy directives - FiT, DBEIS
• Energy markets - retail and wholesale, fuel costs
• Low carbon technologies - heat supply (solar, thermal, heat pump, biomass boiler), electricity supply (bodies, PV, biogas, bioethanol), LCOE, capital requirements
• Energy efficiency - reduce consumption, offset demand, waste heat recovery, energy efficient equipment, energy efficient building design, refurbishment.

Question 10

What are the key energy efficiency learnings from the Hythe store?

Answer 10

• Lighting - enhanced dimming controls, light sensors
• Enhanced fans and boiler operation
• Refrigeration - night blinds (reduced refrigeration demand by 30%), active education of e’ees
• Ovens in bakery and hot food - drafted tips of ovens using equipment

Question 11

What are the impacts of fridge doors in supermarkets?

Answer 11

• Research suggests non-intrusive, i.e. no negative impact on sales
• If 3,000 stores used doors, save 820 GWh pa, 93MW coal power and 363 gCO2e/pa (0.19% UK emissions)

Question 12

Describe the hierarchical energy conservation pyramid.

Answer 12

From the base up:

1. Energy analysis - overview of energy needs/equipment in use
2. Energy conservation - simpler behavioural changes, e.g. turn off lights
3. Energy efficiency - upgrade equipment, insulation, motion sensors
4. Time of use management - run off peak, smart grid supermarkets
5. Renewable energy - solar, wind, biomass

Question 13

What are the key things that businesses should do to increase building performance?

Answer 13

• Keep up to date on policies/markets
• Be aware of how they use energy
• Know the best times to reduce energy costs
• Know key technology trade-offs
• Make investments to enhance the bottom line (TBL)

Question 14

How can we deliver zero carbon buildings?

Answer 14

• Step change needed
• Most established - biome than CHP -> supermarkets already have a relationship with farmers to get fuel from, so stay within their supply chain, and farmers always keen to get additional revenue
• Sainsburys have zero carbon stores in Weymouth and Leicester
• Select best projects to invest in

Question 15

What are the key challenges to decarbonising the built environment?

Answer 15

• Organisations need to strive to enhance energy use
• Good quality metering and data analytics are paramount
• Investment planning with finite resources is challenging
• Decision making and approval for investments is usually made by non-technical management
• Assessing the risk of investments needs further work
• Decarbonisation needs to be complemented with energy efficiency