Dr John Gallagher School of Environment, Natural Resources & - - PowerPoint PPT Presentation

Dr John Gallagher

School of Environment, Natural Resources & Geography Bangor University, UK

PRESENTATION OUTLINE

• INTRODUCTION TO HYDRO-BPT
• LCA OF MICRO-HYDROPOWER
• RESULTS & DISCUSSION
• SUMMARY OF CONCLUSIONS
• FUTURE DIRECTIONS

• 4. Wastewater Outfall

e.g. Yorkshire, 180 kW, £127k p.a.

• 1. Reservoir & Water Works

e.g. Dublin, 90 kW, €75k p.a.

• 3. Pressure Reducing Valve
• 2. Break Pressure Tank

ENERGY RECOVERY IN WATER &

WASTEWATER INFRASTRUCTURE

INVESTIGATING THE TECHNICAL

FEASIBILITY OF ENERGY RECOVERY IN THE WATER INDUSTRY USING

MICRO-HYDROPOWER (MHP) ASSESSING THE ENVIRONMENTAL IMPACTS OF THE TECHNOLOGY: LIFE CYCLE ASSESSMENT, CARBON FOOTPRINTING. CREATING OF A GIS DATABASE OF WATER INFRASTRUCTURE AND ITS ENERGY RECOVERY POTENTIAL FOR

THE IRELAND-WALES REGION.

DEVELOPMENT OF A BUSINESS / COLLABORATION MODEL FOR THE IMPLEMENTATION OF ENERGY RECOVERY BY INDUSTRY STAKEHOLDERS IN PRACTICE.

ENGINEERING ENVIRONMENT GIS MAPPING COLLABORATION

LCA OF MICRO-HYDROPOWER

QUANTIFYING THE ENVIRONMENTAL IMPACT OF MICRO-HYDROPOWER IN

THE WATER INDUSTRY USING LIFE CYCLE ASSESSMENT

OBJECTIVES

 Quantify the environmental impacts of three micro-hydropower

(MHP) installations in water infrastructure

 Identify key differences between materials use and construction

practices for these projects

 Determine the carbon payback of the MHP installations and

compare to economic payback

15 kW Pen y Cefn Water Treatment Works 90 kW Vartry Reservoir & Water Treatment Works 140 kW Strata Florida Water Treatment Works  Location: Gwynedd, Wales  Dŵr Cymru Welsh Water  Design capacity: 15 kW  Power output: 12.5 kW  Turbine: Zeropex Difgen  Head: 90-105 m  Flow: 10-30 l/s  Existing housing in place  Gravity fed by Llyn Cynwch reservoir  New installation, flow control from Difgen turbine to DAF treatments system  Location: Wicklow, Ireland  Dublin City Council  Design capacity: 90 kW  Power output: 78 kW  Turbine: Kaplan  Head: 7-16 m  Flow: 580-1200 l/s  Concrete housing constructed  Gravity fed from nearby Vartry reservoir  Replacing outdated Pelton wheel turbine which generated electricity for site since 1940’s  Location: Ceredigion, Wales  Dŵr Cymru Welsh Water  Design capacity: 140 kW  Power output: 110 kW  Turbine: Pelton twin jet  Head: 183-195.5 m  Flow: 100 l/s  GRP kiosk constructed  Fed by Llyn Teifi and Llyn Egnant raw water reservoirs  New installation, existing DAF system on site, 250-300 kW energy consumption on site

RESULTS – ENVIRONMENTAL BURDENS

1.

Normalised life cycle environmental burdens for MHP electricity were lower for most categories assessed

– 2008).

Impact Category Abbrev Units Global Warming Potential GWP kg CO₂ eq. GHG ef w Abiotic Resource Depletion ARD kg Sb eq. P h as a Acidification Potential AP kg SO₂ eq. I s ( Human Toxicity Potential HTP kg 1,4-DCBe eq. S USES s Fossil Resource Depletion FRD kg kJ eq. Dep elec

Table – Life Cycle Assessment Impact Categories Figure – Normalised impact category contributions for MHP installations compared with marginal grid electricity generation (300MW gas combined cycle plant).

RESULTS – COMPONENT BREAKDOWN

2.

Variability in construction practices and material use was evident in range of global warming potential results of 2.14-4.36 g CO2eq./kWh

Figure – Breakdown of environmental impacts of MHP case studies expressed per kWh generated over project 30-year lifespan (solid = constant, hatched = variable)

RESULTS – CARBON PAYBACK

3.

Carbon payback times for MHP installations ranged from 0.16 to 0.31 years (extending to 0.19 to 0.40 years during sensitivity analysis)

 Expressed per kWh generated over project 30-year lifespan  Carbon payback ~10% of financial payback

Case study Impact categories Carbon payback GWP ARDP AP HTP FRDP (g CO2) (g Sb) (g SO2) (g 1,4DCBe) (MJ) (years) 10 kW 2.14 1.4E-04 4.0E-02 10.05 2.7E-02 0.16 90 kW 4.36 1.1E-04 4.3E-02 9.17 1.1E-01 0.31 140 kW 2.78 9.4E-05 3.3E-02 8.91 6.1E-02 0.21

Table – Total environmental impacts of MHP projects for different impact categories and carbon payback time (expressed per kWh generated over project 30-year lifespan).

SUMMARY

An environmental and sustainable design approach to MHP projects could reduce the environmental impacts of the technology

 Environmental impact of MHP (per kWh electricity over nominal project lifespan).

Global warming potential of 2.14 – 4.36 g CO2 eq/kWh

 The carbon payback was estimated to be from 0.16 to 0.31 years  Turbine/generator are consistent components; larger carbon footprint with smaller

installation per kWh capacity

 material selection impacts upon footprint vs project lifespan

FUTURE DIRECTIONS

The carbon intensity of marginal grid electricity will increase in the future, the estimated carbon payback time will increase by 1% annually

 Downward trend of GHG associated with marginal electricity generation

MHP installation Cumulative GHG emissions (t CO2 eq.) 2014

1 2015

2025 2045

2

2050 10 kW

• 7

36 450 1,206 1,379 90 kW

• 86

173 2,658 7,191 8,233 140 kW

• 80

300 3,944 10,592 12,121

1 Assuming MHP installations constructed by the end of 2014. 2 Signifies GHG emissions produced over the 30-year lifespan.

Table – Mitigation forecasting for total GHG emissions offset by MHP installations between 2015 and 2050 (displacements

• f CO2 emissions associated with gas power plant).

FUTURE DIRECTIONS

Installation of MHP by the water industry can provide a 2% reduction to GHG emissions associated with water supply and treatment

 MHP for energy recovery in water infrastructure can generate ~18 GWh of

electricity in Ireland and Wales

 The installations would add 1,700 t CO2 eq. to the footprint of the industry

 Carbon payback

 Offset approximately 5,750 t CO2 eq. per year  2% reduction (20 g CO2 eq. per m3 of water) in the GHG emissions associated with water

supply and treatment (~1 kg CO2 per m3, (Defra, 2012))