It is no longer news that AI is driving incredible demand for electricity.You may have read that data centers were using 6% of the electricity supply in the UK and the US as of May this year, or that these centers require 40% more energy than originally expected. Electric vehicles, heat pumps, and the growth of locally generated renewable energy are cranking up the pressure on an already complex energy system. But the physical grid is only part of the infrastructure that now has to change.Energy companies depend on a complex digital backbone to keep the business moving. ERP, finance, procurement, HR, customer systems, and more all support essential services. Regulatory obligations don’t disappear just because an IT transformation is underway.In most industries, leaders might look for a quiet weekend to complete a major system migration. Retail brands, for example, can literally change their entire platform overnight, with some careful planning.Energy companies do not have that luxury. Demand does not stop. Assets still need to be monitored, and operational teams still need access to the information that helps them make safe decisions.That means downtime must shape the transformation from the outset, rather than being seen as an obstacle to navigate at the end of the process. For organizations supporting critical infrastructure, the real measure of a successful migration is whether the business and its customers can keep operating while that change takes place.Move less, move smarterAchieving this means wrestling with cumbersome legacy technology estates that have slowly grown over decades of acquisitions, divestments, regulatory change, and necessary short-term fixes.The result is a web of heavily customized platforms, duplicated records, undocumented dependencies, and data that has outlived the process it was originally created to support. Change one part without understanding the rest, and the consequences can surface somewhere completely unexpected.The National Grid offers a useful sense of the scale involved. One of its key S/4 systems alone contains around 1.9 terabytes of data, before accounting for its legacy ECC and HR environments or 20 years of financial information. The organization has also completed three divestments in six years, requiring its data estate to keep changing alongside the structure of the business.A migration at this scale is not automatically a modernization. A ‘lift and shift’ from the existing environment into a new one can inadvertently preserve the very complexity that made transformation necessary in the first place.Before anything is moved, energy providers therefore need a clear view of what they hold, what the business still depends on, and what no longer belongs in the live environment. Some data must remain immediately accessible. Some must be retained for regulatory or contractual reasons. Other information can be archived, consolidated, or removed altogether.That work may not sound as dramatic as a major system launch, but it is what determines whether an organization emerges with a cleaner, more adaptable platform – or falls into the trap of recreating yesterday’s problems in a more expensive environment. What are you migrating?Once you understand what is inside the estate, the next question is not simply how to move it. It is what you move, and what you leave behind.Legacy systems accumulate data almost by default. Energy companies have legal, regulatory, and contractual responsibilities that may extend for years, including for parts of the business they no longer own.Organizations should separate the data that is needed to run the business from the data that only needs to remain accessible. Completed transactions, technical logs, duplicate records, and data inherited through previous acquisitions or divestments can remain long after their operational value has disappeared.Cleaning and archiving that information, making it available again when required, is a fundamental measure of success here. This simultaneously makes the migration smaller and the target environment healthier. Teams gain a clearer view of the information they use and can avoid carrying unnecessary complexity into every project that follows.This is becoming a regulatory priority as well as an operational one. In January 2026, Ofgem expanded its Data Best Practice framework across industry codes, emphasizing the need for energy providers to understand, structure, and manage data consistently. The message was that data should be governed according to its value, rather than simply accumulated.The same discipline is important in testing. Transformation teams often need realistic copies of production data to confirm that payroll, finance, integrations, and other critical processes will behave correctly. But those copies may contain names, addresses, banking details, or sensitive employee and customer information.Simply avoiding that data is not an option, because inadequate testing creates its own operational risk. It needs to be masked or scrambled in a way that protects the individuals concerned without making the test environment useless.In this context, selective migration becomes an opportunity: a chance to decide what the future system should contain. If you’re able to protect sensitive information properly and remove some of the baggage that is making change so difficult in the first place, the organization is in a good position to plan how to move what remains without bringing the business to a halt.Keep the business liveOnce organizations have reduced what needs to be migrated, they can turn to the question that matters most: how to complete the move without bringing essential processes to a halt.Traditionally, that has meant choosing between a phased migration and a single ‘big bang’ cutover. The first can leave old and new systems operating alongside one another for months. The second concentrates considerable risk into one carefully planned event.But those are not the only options. With a near-zero-downtime approach, most data can be transferred while the existing system remains operational. Changes made during that process are captured and synchronized separately, leaving only a small final set to be moved during a tightly controlled cutover.This migration must be rehearsed, the target environment tested, and responsibilities agreed across technology and operational teams. Everyone needs to know which processes can pause, which cannot, and what happens if the cutover does not proceed as expected.For energy companies, speed and continuity shouldn’t be seen as competing objectives. Moving less data through a controlled, well-rehearsed process allows the organization to modernize while the essential work beneath it continues.Build for what comes nextFor critical national infrastructure and the energy companies that run it, a successful transformation should do more than get them to the next go-live. A cleaner core, supported by well-governed data, makes every subsequent change easier – whether that means adopting AI, moving further into the cloud, responding to new regulation, or managing another acquisition or divestment.Energy companies cannot afford to stop evolving, because the infrastructure, demand patterns, and risks around them will not stand still. Underlying systems must be equally capable of change.We've featured the best customer feedback tool.This article was produced as part of TechRadar Pro Perspectives, our channel to feature the best and brightest minds in the technology industry today.The views expressed here are those of the author and are not necessarily those of TechRadarPro or Future plc. If you are interested in contributing find out more here: https://www.techradar.com/pro/perspectives-how-to-submit