Guide to Procurement and Operation of Biomass Heating Systems for County Council Buildings

Nathan Berry

Dorset County Council

November 2012

2

CONTENTS

EXECUTIVE SUMMARY 3

1.0 INTRODUCTION 4

2.0 PROJECT MANAGEMENT 5

3.0 DESIGN 8

4.0 CONSTRUCTION AND COMMISSIONING 10

5.0 OPERATION AND MAINTENANCE 11

6.0 FOLLOW UP AND CLIENT CARE 12

APPENDIX 1 ROLE OF THE SUSTAINABLE PROPERTY TEAM

3

EXECUTIVE SUMMARY

This guide has been produced by Dorset County Council’s Sustainable Property Team and in conjunction with an EU Interreg funded project: Sustainable Energy Across the Common Space (SEACS) 1. The guide is intended to be used by Dorset County Council and SEACS partner organisations to facilitate the uptake of biomass heating installations in non-domestic buildings and to improve project outcomes. The main recommendations are as follows:

• Adopt a project management strategy such as BSRIA Soft Landings

• Undertake a feasibility study to determine the most cost effective solution including the option of heat purchase schemes

• Ensure that designs take account of the particular requirements and constraints of biomass boilers

• Appoint specialist biomass design experts and heed their advice

• Include adequate contract clauses to obtain good quality construction and commissioning

• Provide clear advice to building users on how to successfully operate the biomass boilers

• Set up maintenance contracts specific to each boiler

• For existing boilers which are performing poorly, carry out repairs, alterations and re-commissioning as necessary, to reduce the lifecycle costs and the incidence of disruptive breakdowns

Footnote: 1A number of Dorset schools are participating in the SEACS (Sustainable Energy Across the Common Space) project. ‘Tackling the Energy Challenge Together’ is the vision of the SEACS project, bringing together three UK local authorities: Devon County Council, Dorset County Council and Wiltshire County Council, along with two French local authorities in Brittany: Conseil General des Cotes d’Armor and Lannion-Tregor Agglomeration. SEACS is about empowering and inspiring people on each side of the English Channel to actively reduce their energy consumption. For further information about SEACS please refer to http://www.seacs.info/home

4

1.0 INTRODUCTION

Background Dorset County Council has a commitment to reduce its carbon dioxide emissions by 30% by 2020, is a participant in the government’s Carbon Reduction Commitment scheme (CRC) and is also required to report annually on all of its greenhouse gas emissions. Dorset County Council has had an energy conservation programme since 1979 which has implemented a range of energy efficiency and renewable energy measures across the estate including wind turbines, photo-voltaic panels and biomass boilers. Biomass heating offers one of the largest carbon reduction measures available for an individual property. Wood chip represents a CO2 reduction of 91% compared with gas and 93% compared with oil. Wood pellet represents a CO2 reduction of 79% compared with gas and 84% compared with oil. Dorset County Council has currently installed biomass boilers at five sites and a sixth is under construction. SEACS partner organisations also have a number of biomass systems and are in process of procuring further installations in the near future. Aims This guide has been produced by Dorset County Council’s Sustainable Property Team to assist the uptake of biomass heating systems in Dorset properties and ensure that the systems installed make a significant contribution to carbon reduction whilst also meeting the operational requirements of the properties. The recommendations have been drawn up from operational experience with the existing biomass boilers to ensure that lessons learnt are incorporated into future biomass heating projects. Distribution It is intended that this report would be useful to all those within Dorset County Council, SEACS partner organisations and relevant external consultants involved in providing and maintaining heating systems, including for example designers, project managers, clerks of works, property surveyors and premises managers.

5

2.0 PROJECT MANAGEMENT

Dorset County Council and partner organisations should continue to pursue biomass heating for both retrofit and new-build wherever practicable, but with a methodology imposed to ensure that the particular requirements of biomass boilers are taken into account. The following activities are suggested as a minimum requirement.

2.1 Feasibility Study Before commencing any biomass project a feasibility study should be undertaken to ensure that biomass heating is appropriate to the property and to the premises staff. The feasibility study should consider the following aspects:

• type of fuel available at the site

• daily and seasonal heat load profiles

• type of user and availability of premises manager

• space available for plant and fuel store

• accessibility for fuel deliveries

• proximity of suitable fuel sources

• whether to purchase and operate the plant, or alternatively purchase heat only, via a heat

supply company (HSCo)

2.2 Methodology BSRIA Soft Landings Core Principles should be considered to ensure that projects are properly established, procured and handed over, but noting that this scheme is intended to be adopted in its entirety, not by extracting particular aspects and applying them selectively. Refer to www.softlandings.org.uk for more information. The project manager should produce and maintain a project plan detailing all of the key elements including budget, timescales, project team members and client brief. The project manager should produce a project programme ensuring that sufficient time is allowed for the following activities:

• Feasibility study

• Appointment of project team

• Design, design review and approval process

• Construction, procurement, equipment lead times

• Installation

• Mechanical and electrical tests on completion

• Production of defects lists and completion of remedial works

• Commissioning

• Handover and training of client / end users

• Provision of Operation and Maintenance (O&M) manuals

• Seasonal or repeat commissioning

• Follow up client care

• Project review and recording of lessons learnt

6

2.3 Project Team For a large multidiscipline or new-build project the whole biomass plant should be a primary consideration in the site layout. The design team should include a biomass design specialist to guide the overall scheme design from the earliest stages. The specialist should have a good track record and be issued with a clear client brief including timescales, duties and outputs. The specialist should be appointed by the lead designer whether this is Dorset County Council or an external consultant, to ensure that his advice is heeded by the designer and that the designer retains liability for the overall scheme design. During construction a client representative should check progress and quality. Depending on the scale and complexity of the installation, this role could be undertaken by a property surveyor, mechanical and electrical (M&E) designer, or a Clerk of Works, provided that they have sufficient technical knowledge and time allocated on site to undertake this work.

2.4 Design Review The design should be reviewed sufficiently early in the project to enable alterations to be made before construction. The design review should verify that the following aspects as a minimum have been taken into account:

• Hydraulic design in accordance with boiler manufacturer’s requirements

• Plant room design to facilitate maintenance

• Boiler specification to include labour saving features and minimised life cycle costs

• Seasonal commissioning

• Maintenance for first year of operation

• Provision of fuel for commissioning and first month of operation

• Reference installations.

The end user should be present at the design review so that the boiler operating requirements and levels of attendance can be fully explained to them. Comments / queries raised by the premises manager or site representative should be recorded and responded to by the project manager. Current Dorset County Council policy is that design consultants are appointed on the basis of being expert and that their designs should not require verification by Dorset County Council. However, when using external consultants a design review should still take place. The contract should state that the design review will not limit the consultant’s obligation to provide a design which is fit for purpose, or increase Dorset County Council’s acceptance of design liability in any way. When using external consultants the design review should be linked to a payment stage.

7

2.5 Designer Risk Assessment Designers should undertake a Designer Risk Assessment as required in CDM Regulations. A suggestion of risks to be considered / designed out would be as follows:

• Access difficult due to poor equipment layout / obstructions

• Smoke / fumes / dust / carbon monoxide

• Trip hazards

• Head height objects

• Lone working

• Heat emitted / unpleasant working conditions / possible burns

• Hot ash – fire risk

8

3.0 DESIGN

3.1 Hydraulic Design

Most boiler manufacturers provide a schematic showing the recommended hydraulic circuit design. The designer should refer to this schematic and adhere to it as far as possible. The designer should document any variations from the schematic and the reasons for doing so. If the design is by an external consultant, it should be submitted to Dorset County Council for comments.

3.2 Load Profiles

The designer should produce a schedule of forecast heat loads including daily and seasonal patterns. The designer should then assess the implications of running a biomass boiler to meet the loads in terms of fuel cost, maintenance cost and level of attendance required. Finally, the designer should consult the end user about the options for meeting the loads and document any decisions made. The designer should calculate the hot water demand and review the options for provision of hot water, including for example:

• A calorifier or heat exchanger with the biomass boiler running all year

• A calorifier or heat exchanger with a gas back up boiler generating hot water in spring and autumn.

• Point of use electric water heaters

3.3 Boiler Specification

For larger biomass boilers the type of cleaning regime that will be required can be determined at selection stage. Various options such as automatic tube cleaning can be incorporated to either eliminate or at least minimise the amount of manual cleaning required inside the boiler. If these labour saving options are not specified, there will be additional operating costs associated with the premises manager’s time to shut down, internally clean and re-fire the boiler when cleaning is required, together with the additional cost and carbon emissions associated with an alternative heat source during the boiler outage. The designer should assess the total operating costs of a proposed biomass boiler including fuel, maintenance, cleaning and backup heat supply. The costs of any options which improve operability should be evaluated and the payback periods calculated. Options with a payback of less than 5 years should be selected automatically. Options with a payback of 5 to 10 years should be offered to the client for comment. If any of these options are deselected at a later stage, the designer should provide a statement detailing the effects of this change on the operating regime. The design proposals should include an assessment of the total costs / benefits for each boiler option, rather than just purchase price. This assessment will involve mainly lifecycle costs including fuel consumption, maintenance, routine attendance requirements, etc, but also needs to consider the likelihood of reliability problems in the future. The reliability aspects could be scored using historic data for example number of units installed, number of breakdowns, breakdown response times, references from other purchasers, etc.

9

The boiler selection process should eliminate models which require frequent internal cleaning. The boiler should be equipped with a de-ashing auger to discharge the ash into a container which can be readily removed from the plant room.

3.4 Plant Room Layout

The designer should obtain details of the boiler and preferably select a unit which avoids the need for lifting heavy components, but if unavoidable include a suitable lifting beam in the plant room design. The design of the ancillary M&E equipment must be sufficiently detailed to ensure that items requiring regular maintenance are easily accessible and not obstructed by fixed equipment – this aspect can not be left up to the installer to resolve on site. The plant room should also be laid out to facilitate easy removal of the ash container.

3.5 Controls

Most of Dorset County Council’s properties use a Trend building management system (BMS) to control heating systems. Some biomass boilers incorporate their own controls and require only an enable signal from the Trend BMS, however if this is not the case a Trend strategy can be produced to control all aspects of the plant operation for example boiler firing / modulation, sequencing, rotation, back end protection and buffer tank circulation.

3.6 Fuel Stores

For wood chip systems the lorry tipping point and fuel store arrangement is crucial to the success of the heating system. The outline design of the fuel store and associated road access should be undertaken by a specialist biomass design consultant (see Project Team above) in conjunction with the architect. Designers should base their calculation of fuel store capacity on the evidence of actual capacity from existing installations and ensure that a realistic figure is stated in the resultant proposals which will be used to obtain design approval. For wood chip stores, the specification should include provision of visible fuel level markings on the wall of the fuel store. Designers of wood chip systems should remind end users that they will have to appoint someone to monitor fuel levels. For wood pellet systems designers should investigate current best practice technologies for measuring pellet store contents and select a system with a good track record. Checking the performance of the measurement system should be included within the commissioning requirements and listed in the specification.

3.7 Fuel Deliveries

The designer should address the following aspects

• Lorry access and turning

• Delivery times to suit site operational requirements

• Interaction with vehicles and pedestrians

• Potential nuisance from noise, dust, etc

• Frequency of deliveries under peak load conditions

10

4.0 CONSTRUCTION AND COMMISSIONING

4.1 Completion of Installation The specification should require the installer to verify that all aspects of the works have been completed satisfactorily before commissioning commences. This verification should be documented and witnessed by the client representative (appointed by the project manager) and where appropriate verified technically, eg pressure testing. Any shortcomings in the installation should be recorded on a defects list and a copy forwarded to the installer. Rectification of defects should be linked to a payment stage. The premises manager should not be expected to undertake defects listing.

4.2 Commissioning Biomass boilers do not come set up ready for use from the factory. They require a level of commissioning far in excess of that for an equivalent size gas or oil boiler, particularly in terms of fuel feed rates. The specification should include the requirement for commissioning under full load conditions for whatever period is necessary to achieve stable conditions and satisfactory combustion results. This will of necessity involve commissioning the boiler during the heating season and with the rest of the heating system sufficiently complete to generate a continuous heat demand. The specification should also require the installer to make a return visit after a reasonable operating period, say 1 month, to check performance and make further adjustments as necessary.

Adjustment of walking floor fuel delivery systems should be included in the commissioning schedules. The ability to accurately measure the quantity of heat delivered by a biomass boiler is fundamental to monitoring and maintaining the efficiency of the boilers, and is essential for claiming RHI (Renewable Heat Incentive) payments where available. Heat meters should be included in the works completion checks described above. Setting up of heat meters and recording of initial readings should be included in the commissioning schedules.

4.3 Provision of Fuel for Commissioning The specification should require the installer to provide sufficient fuel for commissioning and for a subsequent period of full-load operation, ie during the heating season, until the operation is considered satisfactory. This would avoid the possibility of the installer blaming the fuel quality for operational problems.

4.4 Improvement of Existing Installations Dorset County Council should implement repairs, alterations and re-commissioning as necessary to restore any poorly performing boilers to optimum efficiency and reliability. This will be far more cost effective than allowing boilers to operate inefficiently and unreliably.

11

5.0 OPERATION AND MAINTENANCE

5.1 Ash removal It is expected that the site premises manager will arrange for periodic emptying of the ash container and disposal in a safe and legal manner. When internal cleaning is required it should be undertaken by a maintenance contractor, unless an automatic system is installed and operational.

5.2 Fuel level monitoring Wood chip stores will require visual inspection approximately once per week. This is not particularly onerous and premises managers are usually quite happy to undertake the task. Premises managers should have written procedures to monitor fuel levels and order fuel deliveries and to ensure that someone covers these tasks during absence such as sick leave. Pellet stores fitted with level detection systems have proved unreliable. For the time being, site staff should continue to visually check fuel levels on a periodic basis. Longer term it is expected that manufacturers will develop more reliable pellet level measurement systems and that these could be procured at a later date when adequately proven.

5.3 Fuel purchasing Purchasers should consider using a fuel supply broker who can assist with selecting a cost effective and reliable fuel supplier and also test the quality of fuel deliveries.

5.4 Planned Maintenance Each of the boilers will require a specific, tailored planned maintenance regime. For schools which participate in BMIS or similar scheme arranged by Dorset County Council, a suitable framework contractor should be appointed to undertake the necessary planned maintenance at each site. The contractor will have to be willing to get a number of technicians trained by the relevant boiler manufacturers. For the existing installations, the appointed maintenance contractor should be asked to undertake a risk assessment of the tasks involved, review how they will manage these risks, and where additional costs are involved, allow for them in their contract negotiations. A periodic inspection of pellet stores should be carried out to check for the presence of loose pellets, dust, bag damage, etc and cleaning or repairs arranged as necessary. This inspection could be done annually initially, and the frequency adjusted if necessary based on operating experience.

12

6.0 FOLLOW UP AND CLIENT CARE

Following project completion and handover a number of activities could be undertaken to ensure that the system continues to operate satisfactorily and to improve the future take up of biomass heating at other sites. The following list is suggested as a starting point, to be further developed or adapted for each site as appropriate.

• Post project review

• Seasonal commissioning

• Gathering and recording of heat metering data

• Gathering and recording of RHI payments received

• Gathering and recording of fuel consumption

• Calculation of boiler thermal efficiency

• Assessment of overall heating system performance

• Assessment of building energy performance

• Assessment of boiler reliability

• Client satisfaction questionnaire and feedback

• Review of operability and maintenance issues eg maintenance contractor feedback

• Request for client testimonials to support future biomass project proposals

• Production of a case study

13

APPENDIX 1

ROLE OF THE SUSTAINABLE PROPERTY TEAM Dorset County Council’s Sustainable Property Team provides assistance and advice on a wide range of energy management and sustainability issues to reduce energy bills and improve the carbon footprint of its buildings including:

• Assistance with identifying and implementing short payback energy efficiency projects such as loft and cavity wall insulation, thermostatic radiator valves and timeswitches

• Investigation of heating and hot water control queries and adjustment of settings where necessary

• Responding to Trend BMS alarms and notification of the Maintenance Helpdesk where plant faults are detected

• Statutory building energy performance reporting including Display Energy Certificates, Energy Performance Certificates and Carbon Reduction Commitment

• Advice on energy tariffs, utility billing and metering

• Provision of competitively tendered energy contracts, bill validation and payment

• Training in efficient operation of building services

• Assistance with identifying and implementing longer payback energy efficiency projects such as draughtproofing, glazing, installation of Trend BMS, etc

• Full building energy audits including detailed building energy performance analysis and review of energy saving opportunities

• Assistance with obtaining project funding including advice on funding applications for government and non government schemes

• Assistance with obtaining income from renewable energy systems including Feed in Tariff and Renewable Heat Incentive

• Assistance with awareness raising campaigns and support with behavioural change in schools including educational events, SEACS Project, Eco-Schools, Schools Carbon Reduction Scheme and Light Monitors

• Design advice on new build and refurbishment projects

• Design advice on renewable energy projects Dorset County Council chose to employ an energy efficiency team in the 1980’s specifically to reduce utility costs in its buildings. The role of this team has expanded, as reflected in the new title of Sustainable Property Team. Whilst it is not a legal requirement in the UK for Councils to have a sustainable property team, it is evident that such a team can add value to projects, improve efficiency, reduce energy consumption and carbon emissions, and reduce capital and operational costs.