Minworth Biomethane Grid Injection Simon Farris Severn Trent Water - - PowerPoint PPT Presentation

Minworth Biomethane Grid Injection

Simon Farris Severn Trent Water Renewable Energy Opportunities Manager

Many people will recognise Severn Trent Water as a leading Water and Waste Service Utility

− 100,000 km of underground pipes − 7,000 above ground assets − Serving 4.2 million properties and businesses − Publically owned FTSE 100 Company

Renewable Energy Generation is a rapidly expanding side to our business

− In 2014/15 we generated 250 GWh of electricity – 28% of the company usage − This was achieved through a combination of:

• Sewage Sludge Anaerobic Digestion
• Crop AD
• Food Waste AD (Dec 2014)
• Hydro Generation
• Wind Power (Summer 2014)

− Target is to reach 50% by 2020

Severn Trent Water Renewables

Who are we?

Sewage gas AD with CHP or BtG 55 engines & 1 Water Scrubber on 34 sites (36.5 MW) Crop gas AD & CHP 3 engines on 1 site (3.1 MW)

3

We have 53 MW of generation plant distributed across our region

NEWTOWN STAUNTON HAROLD

HYDRO 6 turbines on 4 sites (1.5 MW) Wind Power 4 turbines on 3 sites (10 MW TIC)

Food Waste AD & CHP 2 engines on 1 site(2.1 MW)

Coleshill (FWAD AD)

Minworth

Why Biomethane to Grid?

• The anaerobic digestion process at Minworth produces a substantial amount
• f biogas c. 3500 Nmch
• When the heat is not required, relative energy conversion is low
• The connection to the electricity grid is restrictive
• Government incentivised form of generating energy
• Very well established technology in Europe, now becoming a major UK

market

• Biogas upgrading has allowed Minworth to expand and diversify the energy

it can produce

0% 20% 40% 60% 80% 100%

CHP - No Heat Use CHP - Heat Used Gas Export Relative Energy Production Efficiencies

Minworth Process Overview – Upgrading Sewage Gas

The Process Operates 4 main process steps

Flow to the National Gas Grid

Propane Supplementing

Why do we need it?

• The gas must be tested it to prove it meets all of the Gas Safety

(Management) Regulations before it can pass into the network.

• Methane cannot meet these requirements on it’s own, it needs a little

help.

35 35.5 36 36.5 37 37.5 38 38.5 39 39.5 Low methane quality High Methane quality With Propane MJ/scm

CV

National Grid Target

Removing Propane

How have we reduced the need?

West Midlands Local Transmission System (High Flow) NG remote Monitoring point STW Grid Entry Unit Propane Biomethane Plant

Why remove Propane?

• Connecting to the local transmission system is substantially more

expensive

• The Propane Cost savings pay for this in 2-3 years
• The Carbon footprint of the plant is substantially lowered
• It is Cheaper, Cleaner and Simpler

Why is this worth it?

How are we able to do this

• National Grid – Installing of Remote Monitoring point and agreement
• f operating principles
• Ofgem – Agreement of methods of operation on site
• CNG Services – Design of control system and operating principles
• Imtech Process – Management of Supply Chain to deliver the right

process equipment and control management systems

• Severn Trent Water – Prepared to manage risks, operate, and utilise

innovative process The development of this solution has required a number of stakeholders to agree

Where we are today

• The plant has now operated for approximately 9 months
• We have produced 38 GWh of renewable gas for Grid Injection –

enough to heat around 2500 UK homes for a year

• Gas production is both stable in terms of it’s Quality and Quantity

− We inject around 19,000 scm of gas each day − The gas is typically between 36.7 and 37.1 MJ/m3 every day

• Plans to expand our generation capability through Advanced

Digestion

• Currently developing future sites to increase generation as a business

The Plant was commissioned on the 25th September 2014