POTENTIAL FOR ENERGY FROM BIOMASS IN THE UK

Alex McBurnie

ENV-2E02

Energy Resources

February 24th 2005

INCLUDING / IGNORING

LOOKING AT: Electricity Heat Transport 15-25 years in the

future

BUT NOT: Energy from Waste

Which would include: Straw Hedge Clippings Sawmill Waste

Which could provide much energy by themselves

ENERGY FROM EXISTING FORESTS

12% of Britain is woodland – 2.8 million hectares (Forestry Commission, 2004)

By 2020 Britain will be producing 10 million tonnes a year more wood than is currently used – and demand is falling (RCEP, 2004)

This level is sustainable assuming restocking matches or exceeds extraction

HOW MUCH ENERGY COULD THIS PRODUCE?

10 million tonnes of wood Energy Content Estimated 20 GJ / Tonne Will therefore contain (not accounting for

energy used in extraction):- 200 million GJ- 200 PJ per Year

NEW PLANTING

Wood Short Rotation Coppice

-4 year cycle-20 year replacement

Longer growth - 15 years

Willow or Poplar Trees For heat, electricity and

CHP production

Non-wood Miscanthus Grass Oilseed rape for

biodiesel Sugar beet for

bioethanol 1 season cylce All have similar energy

contents ~ 20GJ / tonne

USING SET-ASIDE LAND

Under CAP an average (1999-2002) 640 ha land is under set-aside

Much of this lies fallow At yields of 15 tonnes / hectare / year

(conservative estimate) x 640 ha = 9600 tonnes per year

So 10,000 tonnes per year realistic estimate

SET-ASIDE LAND CONTINUED…

10,000 tonnes x 20 GJ = 200,000 GJ 200,000 GJ = 0.2 PJ per Year

USING EXITING AGRICULTURAL LAND

Grade 5 land largely too poor

Grades 1, 2 & 3 best used for food production

Grade 4 ideal for fuel crops

EXISTING LAND CONTINUED…

Grades 4 = 16% of UK agricultural land NFU indicates 20% of UK crops are not

needed for food Suggests that use of grade 4 land will have

no effect on food supply

HOW MUCH?

16% of UK’s 18.5 million hectares agricultural land = 3 million hectares (roughly)

At yields of 15 tonnes / hectare / year = 45 million tonnes

Assuming 20 GJ per tonne this could produce 900 million GJ = 900 PJ per year

SUMMARY OF RAW ENERGY

From exiting forests = 200 PJ From set-aside land = 0.2 PJ From agricultural land = 900 PJ Minus extraction and transport overheads of

0.2 GJ / tonne (from Thetford Forest practical) x 55,010,000 t = >12PJ

Total = 1088.2 PJ per year

HOW WILL THIS BE USED?

EFFICIENCIES CHP (or heat only) =

85% Straight electricity =

30% Road transport = 70%

SO THE TOTAL USEABLE ENERGY PRODUCED COULD BE ANYWHERE BETWEEN 325 PJ and 925 PJ