Bring sugar and water to a simmer in a small saucepan. Cook until sugar is dissolved and cool to room temperature.

Preheat grill to medium-high heat.

Slice lemons in half. Grill, cut side down for 3-4 minutes until cut sides are charred.

When cool enough to handle but still warm, squeeze juice from lemons. You want about a 1 ¼ cups of juice. Strain juice through a mesh strainer or cheese cloth to remove pulp and seeds.

In a pitcher stir together simple syrup, lemon juice and water.

Serve over ice.