Speculation and uncertainty have swirled around South Carolina Electric & Gas for more than a year, ever since the demise of its ambitious plan to build a pair of nuclear reactors north of Columbia.

But for the first time since last summer, SCE&G ratepayers, investors and employees now have a firm idea for what their future — and their power bills — will hold after a decision by state utility regulators on Friday.

Here's how:

What does the state utility regulators' ruling mean for SCE&G ratepayers? 

Here's the short of it: SCE&G will be allowed to charge electricity users $2.3 billion over the next 20 years. That bill will be split up among the company's roughly 720,000 ratepayers, month by month.

That means the typical home will pay $7.10 a month for 1,000 kilowatt-hours of usage, according to an analysis by the Office of Regulatory Staff, the state's utility watchdog agency. And unlike previous plans for SCE&G's rates, that number will be locked in for 20 years, instead of starting higher and tapering off over time.

In other words, the typical home will pay another $1,700 or so before it's all said and done. All in all, ratepayers will be on the hook for a sum of money that roughly equals the amount they've poured into the project in the decade since it began.

That's far better than ratepayers initially feared last year. If things stayed as they were when the nuclear project ended, they'd have been on the hook for about $7,400.

But then, the final outcome leaves electricity rates higher than they could have been. The Office of Regulatory Staff asked for additional savings — about $600 million over two decades. SCE&G warned that those extra cuts would send its owner-to-be, Dominion Energy, packing.

So, will my bill change?

Not by a lot. The state Legislature ordered SCE&G to temporarily cut its electricity rates over the summer, and that took most of the nuclear costs out of power bills.

Lawmakers thought it would be unconstitutional to demand a permanent rate cut, but they wanted to buy ratepayers at least a few months of relief. So the rate they set only lasted until regulators could make a permanent decision.

The Public Service Commission, the state's utility regulators, landed on a rate near where the Legislature did. Customers will essentially forego savings from federal tax cuts, which will cover the remaining cost of the reactors. Residential customers will pay about $5 a month on average for the reactors, down from $27.

The upshot: While the inner workings of SCE&G's rates are being changed, the end result is the same. Your bill should be similar to what it has been since August.

What ever happened to my $1,000 refund?

Virginia-based Dominion splashed into South Carolina at the start of the year when it offered to buy SCE&G's parent company, SCANA Corp., and cut refund checks for its ratepayers — $1,000 for the typical home.

The offer was played on TV commercials and radio spots, and it was floated on a flyer slipped into customers' bills. Over and over, the message repeated: $1,000 cash could buy a lot.

Ratepayers won't get that money in a check, but the refund is still buying a lot. SCE&G is essentially applying that money toward lower rates. So instead of a check, you'll get smaller bills instead.

The rate savings are also supposed to make up for a big settlement check SCE&G received from the project's contractor last year, money that ratepayers were entitled to get.

“Customers would have been paying back whatever they got in a short period,” regulator Elliott Elam said.

It's still possible you'll get some kind of a check in the mail, though. SCE&G settled a class-action lawsuit last month in return for what will be a much smaller refund.

What does the decision mean for SCANA shareholders? 

Shareholders in SCE&G's parent company have had a rough couple of years. Shares of SCANA soared during the nuclear project, but they have been hammered by uncertainty and a political environment that has been testy at best.

At the deepest nadir for SCANA, investors' stake in the company lost half its value. But their fortunes have improved in the last few months as optimism grew that Dominion would pull off its buyout attempt.

When the deal closes, SCANA investors will receive about two-thirds of a share of Dominion stock for every share of SCANA stock they own. It essentially gives them a life raft out of a sinking investment.

That process won't happen immediately, and in the meantime, SCANA investors are likely to benefit: The company's shares soared more than 6 percent as the last doubts about the Dominion deal's prospects were wrung out of its stock price.

What does the decision mean for the class action lawsuits filed by SCE&G customers? 

The utility regulators' ruling on Friday also allows SCANA and Dominion to move forward with a class-action settlement in state court. 

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Several law firms representing SCE&G customers sued the company in state court last year, just days after the project was cancelled. But late last month, SCANA and Dominion's lawyers convinced the ratepayers' attorneys to settle the case for $115 million and whatever money they could make from the sale of several of the utility's properties. 

The class-action settlement was contingent on SCANA and Dominion getting what they wanted from the Public Service Commission. Now that they have, a judge can consider whether the legal settlement is "fair and reasonable." 

SCE&G former and current ratepayers can voice their support or opposition to that settlement at a "fairness hearing." The date for that hearing has not been set.  

What does the decision mean for SCE&G and SCANA employees? 

SCE&G employees will keep their jobs — or their paychecks — through at least the summer of 2020, but it's ultimately unclear how Dominion will staff the utility once the merger is complete.

Dominion has promised to keep a South Carolina-based president for SCE&G, and it committed to keeping the utility's headquarters in Cayce, just outside Columbia. And most of the jobs that keep the lights on aren't going anywhere: Power plants will still need to be run and electric lines maintained.

Less certain is the future of the back-office jobs that SCANA needed as a big employer and a publicly traded company. Dominion has said that it will try to offer jobs elsewhere in the company to employees who lose work.

SCANA and SCE&G also remain subjects in investigations into the nuclear project by the FBI, the Securities and Exchange Commission and state law enforcement.

What does the decision mean for Dominion Energy? 

The order on Friday all but guarantees that Dominion Energy will takeover SCANA and electric and gas businesses in South Carolina, North Carolina and Georgia. 

Dominion, a giant in the energy industry, will get even bigger. The company will supply roughly 6.5 million ratepayers with electricity and natural gas in eight states once the deal closes, according to the company. It's worth roughly $50 billion on Wall Street. 

The takeover of SCANA drastically expands Dominion's business in South Carolina. It had already purchased SCANA's gas transmission lines in the state in 2015, but it now powers the lower half of the state, from Greenwood to Beaufort and Charleston to Columbia.

The deal also gives Dominion, for the first time, hundreds of thousands of residential and industrial customers in the Palmetto State that can't go anywhere else for electricity or natural gas.  

It could also give Dominion a legal justification to expand the $6.5 billion Atlantic Coast Pipeline into South Carolina. That interstate pipeline current ends in Lumberton, North Carolina. 

Reach Andrew Brown at 843-708-1830 or follow him on Twitter @andy_ed_brown.