Independent engineering for solar, storage and hybrid assets.
Technical due diligence, asset performance, owner's engineering, contract review and expert witness services for lenders, investors, developers, IPPs and EPCs across the UK, Ireland and the EU. No EPC business, no equipment sales, no commission.
Owner of a home, office or small commercial roof? Our residential site is written for you →
- 11 yrsin utility-scale solar engineering
- 2 GW+of PV assets reviewed, designed or operated
- 9countries worked in, from the UK to Japan
- 100%independent: no EPC, no equipment sales, no commission
Engineering on the owner's and lender's side of the table
Four kinds of organisation instruct us. Each has a different question; the method behind the answer is the same.
An engineer’s opinion the investment committee can rely on
Buy-side, sell-side and lender-side technical due diligence, condition assessment on operating assets, and contract review from a reviewer who has also built and operated what is being bought.
How we help → Asset owners, IPPs and asset managersWhat the fleet should be producing, what it is, and where the gap goes
Performance reconciliation, string-level analysis, inverter fleet position and O&M contract scrutiny, on one site or across a portfolio, with every finding priced in yield and in money.
How we help → Developers and EPCsOwner’s engineering from specification to takeover
Technical representation through feasibility, specification, tender, contract negotiation, construction monitoring, commissioning witness and handover, on solar, storage and hybrid projects.
How we help → Solicitors, insurers and adjudicatorsTechnical evidence on underperformance, defects and delay
Failure investigation, data analysis and expert reports for litigation, arbitration and adjudication, prepared to CPR Part 35 and the Scottish equivalents, with early-stage views on the strength of a claim.
How we help → Homes, offices and small businessesLooking for help with a single building?
Second opinions on quotes, small-project support and contract checks live on our residential site, written for people who are not in the industry.
Go to the residential site →From a single operating site to a portfolio under transaction
Asset Health Check
One operating site, a defined method and a fixed fee: performance reconciled against a rebuilt expectation, faults located to string and inverter level, O&M and warranty position tested, and every finding priced in yield and in money.
- Measured output against a rebuilt expectation from real weather data
- String and inverter-level analysis to locate where the yield is going
- Degradation against warranty, and inverter fleet position
Portfolio Review
Every asset in the fleet measured on the same basis, ranked by the gap between what it should produce and what it does, with a capex model that puts every fix in payback order and a repowering case where one exists.
- Every site measured on the same basis
- A league table of performance in kWh and in money
- A capex model ranking every remediation by payback
Due diligence
Before money changes hands, we establish whether the asset is what it is represented to be, whether it will produce what the model says, and which of its problems will actually cost money, to the deal timetable.
- Design and build reviewed against the represented specification
- Yield assessment assumptions tested, P50/P90 basis checked
- Equipment bankability and obsolescence exposure
Owner's Engineer
The engineer on the owner's side of an EPC contract: we specify what should be built, run the tender so bids are comparable, negotiate the technical terms, monitor construction and witness the tests, so that what is handed over is what was paid for.
- Feasibility, load matching and grid connection strategy
- Technical specification and employer's requirements
- Tender management and normalised bid evaluation
Contract review
Solar contracts are technical documents in legal clothing. We read the clauses counsel reads past, such as how the performance ratio is tested and what the O&M scope excludes, and tell the client and their solicitor what each will do in practice.
- EPC performance tests, guarantees and liquidated damages
- O&M and asset management scopes, SLAs and exclusions
- PPAs, leases and grid agreements: the technical obligations
Expert witness
When a solar or battery system has gone wrong and the parties disagree about why, we investigate, analyse the data and write a report that a court, arbitrator or adjudicator can rely on, starting with an early view on the strength of the claim.
- Preliminary technical view on the strength of a claim
- Site inspection before evidence is disturbed
- Data analysis of underperformance, defects and delay
A reviewer who has also built and operated the assets
Most technical advisers have only ever reviewed. Apex was founded by an engineer who spent the first part of his career doing due diligence for lenders, and the next seven years on the other side of that table: designing utility-scale plants, running plant engineering for an owner-operator, and building the systems that watch an operating fleet.
That combination is the difference between a red-flag register and an opinion about which flags will actually cost money. It is also why our reports put the findings that change the number at the front, in language the investment committee can act on.
Three commitments
Independent, in writing
Apex takes no commission, referral fee or other consideration from any installer, manufacturer, contractor or supplier. Every report carries a declaration of interest. The policy is published, with the relationships that could test it.
Findings first, evidence behind
Reports are written to be used in a committee paper or a letter of claim: what changes the number, what it is worth, and what to do, with the completeness evidence behind it rather than in front of it.
Fixed scope, fixed fee
Defined work is scoped and priced in writing before it starts. Transaction timetables do not move because the technical adviser is busy.
What clients and colleagues say
I can confidently say that anyone who has the opportunity to work with Dale Barnard is very fortunate. His professionalism, creativity and supportive nature make him an asset to any client.
I have come to highly appreciate Dale’s expertise as an engineer, and just as important, his ability to explain complex technical issues to non-engineers.
Dale’s approach is as a flexible and sympathetic leader, where morale, integrity and motivation are high. Dale is loyal to the direction of the clients and is an extremely effective communicator.
Dale Barnard, MEng MIET
Eleven years in solar: technical due diligence at SgurrEnergy, senior project engineering at European Energy, then Head of Systems and Analysis, Director of Digital Solutions and Senior Director of Plant Engineering at Better Energy, a utility-scale developer and owner-operator in Copenhagen.
Dale founded Apex in 2025 to bring that owner-operator perspective to the transaction, operating and dispute work where it is rarest. Assets in nine countries, more than 2 GW reviewed or engineered.
Tell us about the asset, the transaction or the dispute
Most engagements start with a short call about what you are trying to decide and by when. We will tell you what we would do, what it would cost, and whether you need us at all.