Introduction
Who is Top Energy?
Top Energy is a northland electricity distribution and generation company. Since established in 1935, Top Energy has grown to manage assets of over $680 million and employ over 150 staff members, all while providing high quality power services to the region.
Who is Safety Solutions?
Safety Solutions Ltd (SSL) is an independent process safety consulting and training organisation. Our main consulting services include:
● Process Safety workshop facilitation
● Process Safety audits
● Safety Management system development
● Safety Case development for High Hazard Assets
● Functional Safety – assessment, design, management
● Hazard and Risk Studies.
● Hazardous area classification
● Alarm Management
● SCE verification
We have an established training portfolio which includes technical and management courses. These can be viewed here.
Top Energy Overview
Power Stations
Top Energy has 3 main power stations surrounding Ngawha Springs containing 4 Ormat Energy Converters (OEC’s), which combined produces over 100 MW of power.
Process
At each power station, wells are drilled down into the geothermal field, the geothermal fluid surfaces and is separated into steam and geothermal liquid (brine) which is used to heat pentane. The vaporised pentane is used to spin turbines which is used to generate electricity. The condensed steam and brine are then reinjected into the geothermal field.
Carbon Zero
Even though geothermal energy is renewable the process does also bring non-condensable gases (mainly CO2 and H2S) up from the geothermal field, these have traditionally been vented to atmosphere. By succeeding in the 100% reinjection of non-condensable gases, the Ngawha Geothermal Power Station has become the first geothermal power plant in New Zealand to achieve net carbon zero status.
Our Work
In 2016, Top Energy contacted Safety Solutions to perform a safety case scouting study on their Ngawha binary plants. This was to determine the scope and effort required to develop a Safety Case which would meet the new Major Hazard Regulations 2015/2016.
The study identified that significant work was needed to address gaps in their Safety Management system (SMS) as well as meeting the new requirement of the regulations. Over the next 2 years, Safety Solutions used safety assessment to identified safety critical elements at all 3 OEC’s, worked on Improvements to the SMS and development of a comprehensive emergency response plan to create a full safety case for Top Energy.
This was the most comprehensive job we have completed, as it included HAZOP facilitation, Risk assessments (LOPA), Consequence modelling, SCE management, emergency planning and the development of SMS Elements.
An example of work we did to meet the new MHF regulations for Top Energy was the emergency response flip chart (to compliment the emergency planning SMS element). Here the hazards were identified and developed through the safety assessment and implemented into a quick reference document on response to emergencies related to all identified hazards.
After the original safety case was completed by Safety Solutions, Top Energy began construction of OEC 4. This meant the Safety Solutions team were given the challenge to update the safety case to include OEC 4 prior to the review of the safety case by WorkSafe. This was accomplished on time and was accepted by WorkSafe with minimal issues.
Since 2016, Top Energy has participated in several of our process safety training courses (in both E-Learning and Face to Face formats), using it to develop competence in their staff from executives to frontline workers.
Recent Work
Safety Solutions has been helping Top Energy by performing numerous SMS audits, safety assessments and hazard reviews on their plants. One such hazard review was when the Ngawha Power station was modified to reinject CO2 rather than emit to the atmosphere.
In 2023/24 SSL have been continuing to support Top Energy with the revalidate their safety case for resubmission (Required ever 5 years).
Engagement Benefits
Some of the benefits which Top Energy received by working with Safety Solutions were;
● A high-quality Safety Case including OEC4 was submitted on time to WorkSafe.
● Acceptance of the safety case with very little clarifications required.
● Quality hazard reviews for numerous processes, including the zero-emission Ngawha Power station reinjection process.
● Staff, management and executive competence in process safety was raised to deliver value over the long term through the completion of the training courses.
What Made It Work?
Multiple factors led to the successful outcome we had with Top Energy.
Collaboration
The collaboration and communication between Top Energy and Safety Solutions staff was very effective and efficient.
Key Staff
Both Safety Solutions and Top Energy had key staff driving the program and encouraging productive collaboration between the companies.